Phowa (Tibetan: འཕོ་བ་; Wylie: 'pho ba; also spelled Powa or Poa phonetically; Sanskrit: saṃkrānti) is a Vajrayāna Buddhist meditation practice. It may be described as "the practice of conscious dying", "transference of consciousness at the time of death", "mindstream transference", or “enlightenment without meditation” (Wylie: ma-sgom sangs-rgyas).
The method can be applied at the moment of death to transfer one's consciousness through the top of the head directly into a Buddha-field of one’s choice. By so doing, one bypasses some of the typical experiences that are said to occur after death. Example destinations are Sukhāvatī, Abhirati, Ghanavyūha, Aṭakāvatī, Mount Potala, the Copper-Colored Mountain (Wylie: Zangs-mdog dpal-ri), and Tuṣita; the most popular in Chinese, Japanese and Tibetan Buddhism is Sukhavati. Phowa is also performed by specialists (Wylie: ’pho-’debs bla-ma) on the behalf of the deceased, as a post-mortem ritual. 
The mark of a successful Phowa practice is a small drop of blood directly from the center of the vertex. To demonstrate a successful practice traditionally a Kusha-grass was pushed into the small opening created in the fontanel.
Nāropa’s teachings describe a second method of ’pho-ba that entails the transference of one’s consciousness to another body (Wylie: ’pho-ba grong-’jug). Milarepa’s query regarding these teachings forced Marpa to search for explanatory treatises on the subject among his Indian manuscripts, and, having found none, to return to India to obtain more scriptures.
The Drikung Kagyu school of Tibetan Buddhism is known for their phowa teachings. A major pilgrimage and cultural celebration is known in the Tibetan world as the Great Drikung Phowa (Wylie: ’Bri-gung ’pho-ba chen-mo). This festival was traditionally held once in every twelve-year calendrical cycle, and its last observance took place in August 1992 in gTer-sgrom, Central Tibet, after a hiatus of 36 years due to a ban enforced by the Chinese authorities. Choeje Ayang Rinpoche from Eastern Tibet belongs to the Drikung school and is an authority on Buddhist afterlife rituals; he gives teachings and initiations to the practice of phowa annually in Bodh Gaya, India.
Phowa has many different meanings; in Tibetan it means "transferring consciousness." The highest form is known as the phowa of the dharmakaya which is meditation on the great perfection. When you do Dzogchen meditation, there's no need to transfer anything, because there's nothing to transfer, no place to transfer it, nor anyone to do it. That's the highest, and greatest phowa practice.
The Japanese scientist, doctor Hirosi Motoyama, studied psychophysiological action of a phowa. People practicing phowa were developing same results: physiological changes of nervous system, metabolism and system of acupuncture meridians. Hirosi Motoyama found out on the electroencephalogram that waves of biocurrents of a brain during phowa practice radically differ from the yogis practicing other types of meditation. Researches showed that phowa stimulates a certain part of a brain – a gipotalamus. The stop of usual cogitative activity is also observed.
Subjective signs of successful practice of a phowa consist in emergence of an itch on the top, headaches, emergence of transparent liquid, swelling or softening of tissues round fontanel area. The most reliable sign of success is the emergence of a small opening on the top of the head into which the jackpot blade tip is traditionally inserted to check the success of practice.