How many ways or how may subjects of meditation are there ?
According to Lord Buddha's teaching, there are forty ways or forty subjects of meditation that you can choose to practice. Each way or subject leads to the insight meditation to realize the Four Noble Truths and eliminate greed, anger, and delusion.

Which subject of meditation is suitable or appropriate for me ?
The Lord Buddha taught all his disciples in many different ways of meditation according to their original habits or their temperaments. Then you should observe or notice what your mind, your emotions or your temperaments are likely to be. Sometimes you may feel more passion and other times you may worry or have negative thoughts. There are six kinds of temperament (Carita). They are :
Lustful temperament. By nature most people have passion for all beautiful subjects. The Lord Buddha advised the Buddhist monks to meditate or reflect on the reality of the body, which is composed of blood, bones, urine, feces, saliva, tissues, and internal organs to see if they are really beautiful and clean. The concentrate on the characteristics of a one-day corpse to a ten day-corpse.
Hateful temperament. To get angry or easily irritated, to destroy hatred-there are many subjects of meditation to choose from.
-Yellow device
-Green device
-Red device
-White device
One can also meditate on living- kindness, compassion, sympathetic joy, and equanimity.
Ignorant temperament is not knowing the true meaning of life and nature. A good subject for meditators to practice is breathing meditation in order to have a clean mind and to receive more wisdom.
Devout temperament (saddhacarita). Reflection on the good qualities of Buddha, Dhamma, Buddhist monks, morality, generosity, and quality to be in a divine state are suitable for those who have confidence in Lord Buddha.
Intellectual temperament (buddhicarita). Four subjects of meditation are suitable for educated people : Reflecting on death and eternal peace (Nibbana)and analyzing the reality of loathsomeness of material food, investigating the four elements-earth, water, heat, air-of which the body is composed.
Discursive temperament (vitakkacarita). Sometimes when there is a tendency to worry about everything, it is hard to stop it. A good subject for meditation is : concentrate on breathing; inhale and exhale; keep the mind on the air going in and out of the lungs instead of worrying.
If you cannot determine which temperament you have the most, the Lord Buddha suggested the Middle Way for all practitioners :
1. Earth device
2. Fire device
3. Air device
4. Water device
5. Space device
6. White device
7. Mindfulness on breathing
8. Concentration on the four stages of formless realms. For this one, the practitioner must enter the fourth stage of absorption by concentrating on one of the ten devices
In Buddha's teaching, there are forty subjects of meditation. Individuals can choose to practice any of these forty methods according to their temperaments or as they prefer. Each method leads the practitioner to the path of purification by beginning with concentration until the mind is calm with one-pointedness of that object. The practitioner considers that object as the body-mind is subject to change, sorrow, and decay.

1.The ten Devices (kasina)
Earth kasina. Breathing concentration by visualizing earth or dirt as a device until the picture of earth or dirt is in the mind. Then he can close his eyes, concentrate on breathing and the characteristics of dirt.
Water kasina. Breathing in and out with mindfulness, having any amount of water nearby.
Fire kasina. Visualize candlelight; then close the eyes by concentrating on breathing.
Air kasina. Breathing concentration and visualize air in the mind.
Green kasina. Breathing concentration and visualize a green color in the mind.
Yellow kasina. Breathing concentration and visualize the yellow picture in the mind.
Red kasina. Breathing concentration and visualize re color in the mind.
White kasina. Breathing concentration with white color picture in the mind.
Light kasina. Breathing concentration with any sunlight or electric light picture in the mind.
Space kasina. Breathing concentration and visualize space in the mind.
According to the texts or the Buddha's teaching, the meditator or the teacher should know what kind of temperaments the person has. There are six kinds of temperaments (carita) :
Lustful temperament (raga). To see everything in the world as beautiful.
Hateful temperament (dasacarita). To become angry or easily irritated.
Ignorant temperament (mohacarita). Not knowing the reality of life or nature.
Devout temperament (saddhacarita). To be na?ve or a tendency to be devoted to any belief.
Intellectual temperament (buddhicarita). To be wise or have more intelligence.
Discursive temperament (vitakkacarita). Tendency to worry easily.

2.Ten Impurities of the Body (ten corpses)
From day one to day ten, these methods are used to eradicate the mind's delusions and to know the truth of one's own disgusting body.
Bloated body. Breathing concentration with observation for one day of one's dead body.
Discolored body. Breathing concentration by visualizing in the mind one's dead body for two days.
Festering body. Breathing concentration by focusing on or observing in the mind, a picture of one's dead body for three days.
Dissected body. Breathing concentration and observing in the mind a picture of one's dead body for four days.
Gnawed to pieces. Breathing concentration and observing in the mind a picture of one's dead body for five days.
Scattered in pieces. Breathing concentration and observing in the mind the reality of one's dead body for six days.
Mutilated body. Breathing mindfulness with investigation or observation in the mind of one's dead body for seven days.
Bloody body. Breathing concentration with investigation or observation in the mind of one's dead body for eight days.
Worm-infested body. Breathing concentration with observation in the mind of the reality of one's dead body for nine days.
Skeleton body. Breathing concentration with observation in the mind of the reality of one's dead body for ten days.

3.Recollections of the Buddha (buddhanusati)
By recollecting the Buddha's virtues, one realizes that he is the Exalted One, worthy, fully enlightened, endowed with wisdom and good conduct. He is the knower of all the worlds, caring about the welfare of all creation. He is the incomparable charioteer for the training of individuals; he is teacher of gods and men.
One should concentrate in breathing to calm the mind. Then let the mind work by reflecting and visualizing the virtues and image of the Buddha.
The Buddha is the holiest person as he is completely free of all defilements and thus he is worthy of worship by men and gods.

4.Ten Refletions or Recollections (Anusati)
After calming the mind by focusing on breathing, you can return to meditation or think about the following virtues of Buddha :
Recollection of the Buddha. Investigate the good qualities of the Buddha and why you are following his teachings.
Recollection of the Dhamma (Buddha's doctrine). Investigate Buddha's teachings in the Dhamma . There are five precepts : generosity, meditation about the reality of nature, mind and body; the three characteristics of phenomenal existences, which are subject to change; sorrow and lack of control or decay. Finally his teachings guide us to have inner peace, wisdom, and liberate us from the cycle of birth, aging, sickness, and death to enter Nibbana, the real eternal happiness.
          Recollection of the Sangha. Reflection and concentration on the virtues of noble Buddhist monks who have entered the stream of Nibbana. They have good moral conduct; they are disciples of the Exalted One who follow the Buddha's teachings and teach us how to understand the reality of life and nature. They point out the way for our liberation, to be free from the wheel of life, sickness, and death. They also explain to us the way to Nibbana.
Recollection of Virtue (Silanussati). To concentrate and reflect on the perfection of one's morality (five precepts, eights precepts, 227 precepts). One should remind oneself to have good thoughts, good speech, and good conduct because morality brings no trouble in life and brings peace and happiness in the present life and for many lives to come. Morality is one step up to higher realms or heaven and to Nibbana.
Recollection of Generosity (Caganussati). To concentrate and reflect on one's own charitable offerings. It is the way to get rid of greed. The more you give, the less you have greed. By observing the virtue of giving, you will never be poor in the present life or future life to be rich. For generous people will always find joy in their hearts and they will live peacefully among their good friends. It is the first step to enter sainthood.
There are three gifts of giving:
1. Material gifts to destroy greed.
2. Forgiving, gifts to destroy anger.
3. The gift of self, to separate the spirit from the selfish body, to see that there is on self body in which to cling or attach oneself because it is a decaying body. The spirit will be free from the body and will be liberated. The free spirit will be free from the body and will be liberated. The free spirit with no craving for oneself will attain the final goal of Nibbana.
Recollection of Deities. To concentrate and think about the virtues of deities, Deities are born in higher states because of their good behavior, good faith, morality, charity, knowledge, wisdom, moral shame, and moral dread. Then one should follow these virtues.

          Recollection of the virtues and excellent qualities of Nibbana. The Lord Buddha taught everyone the Noble Eightfold Path, called the Middle Way, which leads to tranquility, realization, enlightenment, and eternal, supreme happiness for all sentient beings, called the stage of Nibbana.
It is difficult to understand the stage of bliss or what Nibbana really feels like unless you meditate on any of the forty kinds of meditation or contemplate on the body, feelings or states of mind, and the five hindrances, five aggregates of grasping, six internal and external sense base, and the four noble truths of suffering. The way is to contemplate the excellent qualities of Nibbana. The meditators should consider the following :
-Nibbana is highest bliss with no greed, no hared, no illusion, no ignorance, no illness, none of the five aggregates, no disappointment.

5.Contemplation on the excellent quality of Nibbana
Nibbana is the excellent state of permanent happiness. There is no rebirth, no aging, no illness, no death, no passion, no water, no fire, no sun, no moon, no air, no darkness, no changing like other states (hell, animal kingdom, heaven, Brahma, human), which are all temporary states.
There are lighter, brighter, all kinds of beautiful things beyond your wishes in Nibbana. There are no animals, no dirt. There are may Lord Buddhas and holy lives filled with sparkle like a diamond, only virtuous spirit people with no craving in Brahma, heaven, or human state can enter Nibbana.
When you reach the state of Nibbana, you will have eternal supreme happiness, supreme contentment with pure spirit and transparent body which can travel anywhere anytime faster than electric light or the sunlight. Nothing can harm the pure spirits of Nibbana because Nibbana is the stage of supreme freedom. The feelings in Nibbana are supreme knowledge with super power.
Nibbana ia a bright, beautiful, magical power of the clear soul composed of transparent Light. It consists of only a pure, special image which is controllable. There are many real pure images of Buddha. You will not be lonely. Some people misunderstand about the pure soul or spirit. It is not the same as the mind as discussed in the Foundation of Mindfulness which is misunderstood by some (cittanupassana).
The way to understand the state of Nibbana is by cutting out all unwholesome thoughts and separating your spirit from the five aggregates (body, feelings, perception, mental formation, consciousness). All five aggregates do not really belong to you. Meditation will help you realize more about the body. Only by transcending the sense of the separate self and merging with Nibbana, you and end the cycle of birth, sickness and death. If one kills oneself of other beings this will result in misery and illness.

6.Recollection of Death (Marananussati)
To concentrate and to consider that one's own death is certain. There is no fear before or after death if we have good conduct, a kind heart, compassion and the realization that only the body decays.
The pure spirit of meditation never results in death. The five aggregates (body, feelings, perception, consciousness, mental formation) are temporary and they are not the same thing as you purified soul. They are separate. The purified soul will go on the higher, better realms. There is nothing good, beautiful or lasting to cling to.

7.Recollection of impure parts of the body (kayagatanusati).
To concentrate on how the body really is or what the body is composed of. The Buddha emphasized in the Tipitaka textbook that to attain enlightenment the monks should meditate on impure parts of the body as a walking copse.
The body does not belong to us. We stay in the body for a short period of time. The mind or our soul does not need to cling to our body or possessions. To practice meditation is to understand that the body and the soul are completely separated. Then we should detach the soul from the body.
The Buddha pointed out that all physical and mental phenomena of existence consist of five groups or five aggregates :

8.The five aggregates of all living beings.
What are the five aggregates of all living beings ?
Human beings and animal beings can be analyzed into five groups of five aggregates according to the Buddha's discovery.
1. Material or corporeality group (Rupa khandha). This group consists of skin, muscle, bone, hair, all the visible or touchable things which are called the earth element; and blood, urine, mucus. Called the water element, combined with air breathing in and out called the air element. Heat regulates the temperature of the body, called the fire element.
2. The feeling group consists of good feelings, bad feelings (Vedanakhandha) and indifferent feelings.
3. Perception group (Sannakhandha) consists of the memory of form, sound, odor, taste, bodily impressions and mental impressions.
4. In the group of mental formations are all kinds of good thoughts, bad thoughts, and emotions.
5. Consciousness means all sensory nerve impulses of the body such as consciousness of cold, heat, pain, soft, hard. This should not mix up with the soul or spirit. It is completely separate.

     - Contemplation on Breathing (Anapananussti). Ana means inhalation and apana means exhalation. Mindfulness of one's own respiration, breathing out and breathing in. The concentration on in and out breathing can lead to jhana. The higher states of consciousness up to jhana (absorption), to one pointedness of the mind, and ultimately to insight, the wisdom that understands the truth of nature. Detachment from the five aggregates (body and mind) leads to enlightenment (Arahatship). Breathing concentration is one of the best subjects upon which to meditate, which appeals equally to all. The Buddha also practiced this breathing meditation before enlightenment and passed away into Nibbana. It id obvious that concentration on respiration not only brings tranquility and a state of transcendence. But also to cultivate insight in order to liberate oneself from the wheel of birth, sickness, and death.
If I want to practice mindfulness of breathing, with no one to guide me, how
do I begin ?
     - First, find a quiet place. The best place is you own room. Then sit comfortably or you can lie down. The important thing to remember is you must train your mind so the body is comfortable and relaxed.
     - Second, investigate your own feelings if you are sad, worried, nervous, depressed, or happy. Whatever you feelings are, try to forget these feelings for a few minutes. This is the way you can control your own mind, not to wander as it used to do.
     - Third, cultivate a spirit of inquiry in you meditation attitude and determine to help yourself get out of this miserable uncertainty and insecure life by liberating yourself from all defilements.
     - Fourth, focus on or observe the sensation of your ordinary breath. Then take three deep breaths to experience the flowing of air in and out from your nostrils. You will try to maintain you attention at three points. When the air touches the nostril down to the chest and to the abdomen, from the abdomen the air moves up to the chest and out through the nostrils.
     - Fifth, breathing has a tranquilizing quality and the same as your mind. The more the mind focuses on steady breathing and relaxing, the more you will feel tranquility, peace, calm, and joy, Your mind may jump out from concentration on breathing and wander somewhere around the world. You should not feel guilty.
To continue, concentrate on respiration. We should know the five levels or factors of breathing meditation:
Lift the mind up to the object of breathing.
Sustain the mind with the breath.
Liberate joy and ecstasy
Happiness and bliss: feeling a new kind of pleasure without dependence on any material objects.
High pure bliss: Recognize that the mind is separate from the painful body, that this mind is sharp and full of wisdom and understanding, that this world is full of illusion. It is the path to purification and destruction of defilements.
In the suttas, this simple method of mindfulness of respiration is explained as follows:
Attentively he breathes in, attentively he breathes out.
One should sit, stand or lie down in a comfortable posture. Then breathe naturally and relax. To keep breathing with more awareness, inhale first and mentally say according to the device, the object you like such as ten devices, Bhudho (Buddha image), or you can count up to ten until you can concentrate on respiration without counting.
The more you concentrate, the more the mind will realize the truth that the body exists only by breathing in and breathing out. The body will die after breathing stops. Thus you will see that the uncertainty of life depends on breathing.

          Breathing meditation is also the best way to eradicate the five obstructions on the path to purification, the five hindrances (Nivorn), and the five obstacles on the path to heavenly states (emancipation) or the progress of meditation.
Sensual desires (Kamacchanda). The attachment to pleasurable sense objects such as form, shape, beauty, sound, odor, taste, and contact. This is regarded as passion to everything we love.
Ill-will (Patical vyapada) is hatred or anger. The undesirable leads to dislike and anger. Not knowing the reality of life, we tend to cling to the desirable objects and we hate the undesirable objects that cause the mind to be upset and miserable later when we are apart from what we are apart from what we like, and we suffer when we stay near the things we don't like.
Laziness and sloth (Thina-middha) is the inert or drowsiness state of mind. These states of mind do not want to work on the good benefit of their own by finding some excuses to correct this laziness of mind, the Buddha advised the following:
- Reflection on the object of moderate food.
- Changing the bodily posture.
- Contemplation on the object of light.
- Living in the open space.
- Good friendship.
- Profitable. Knowledgeable talk.

9.Four Modes of Sublime Conduct (Brahmavihara)
The four modes of sublime conduct are very natural things to meditate upon if you have sympathy and good will for all humankind.
Loving kindness (Metta). It is not passionate hove, but a sincere wish for the genuine welfare of others. How should one practice loving kindness? You can practice loving kindness to yourself first. You will then feel peaceful, happy, and free of suffering.
Compassion (Karuna). To meditate on compassion is to have a kind heart when you see someone poor and suffering with painful sicknesses of the body. You will try to do anything to help that person gain relief from suffering, not expecting anything in return, not even gratitude. The wishes to remove the sufferings of others is the key characterstic.
Sympathetic joy or appreciative joy (Mudita). It is the congratulatory attitude, joy in others' prosperity and success. This feeling is the enemy of jealousy and it helps to build friendship with others.
Equanimity (Upekkha). This concentration of neutral feeling can eradicate the bad feeling of sadness or aversion in case there is nothing we can do or help if the situation gets worse. It keeps the mind balanced from troubles of life such as blame, pain, loss or dishonor.
Anyone who practices one of these four sublime states is said to be living in the moral state of celestial Brahmas.