In her book “Shamanism: The Archaic Techniques of Ecstasy”  Mircea Eliade, elaborates:
“If the word “shaman” is taken to mean any magician, sorcerer, medicine man, or ecstatic found throughout the history of religions and religious ethnology, we arrive at a notion at once extremely complex and extremely vague; it seems, furthermore, to serve no purpose, for we already have the terms “magician” or “sorcerer” to express notions as unlike and as ill-defined as “primitive magic” or “primitive mysticism.
It is here that we see all the advantage of employing the term “shamanism” in its strict and proper sense. For, if we take the trouble to differentiate the shaman from other magicians and medicine men of primitive societies, the identification of shamanic complexes in one or another region immediately acquires definite significance. Magic and magicians are to be found more or less all over the world, whereas shamanism exhibits a particular magical specialty, on which we shall later dwell at length: “mastery over fire,” “magical flight,” and so on. By virtue of this fact, though the shaman is, among other things, a magician, not every magician can properly be termed a shaman. The same distinction must be applied in regard to shamanic healing; every medicine man is a healer, but the shaman employs a method that is his and his alone. As for the shamanic techniques of ecstasy, they do not exhaust all the varieties of ecstatic experience documented in the history of religions and religious ethnology. Hence any ecstatic cannot be considered a shaman; the shaman specializes in a trance during which his soul is believed to leave his body and ascend to the sky or descend to the underworld.”
Historically, it is often associated with Indigenous and tribal societies, and involves belief that shamans, with a connection to the otherworld, have the power to heal the sick, communicate with spirits, and escort souls of the dead to the afterlife. Shamanism is especially associated with the Native Peoples of Siberia in northern Asia, where shamanic practice has been noted for centuries by Asian and Western visitors. It is an ideology that used to be widely practiced in Europe, Asia, Tibet, North and South America, and Africa.
The process of initiation varies from one culture/tribe to another. Here we explain some of the initiation ceremonies by different tribes around the world according to Mircea Eliade’s book “Shamanism: Archaic Techniques of Ecstasy“.
Initiation among the Tungus and the Manchu
In North Asia and elsewhere in the world ecstatic election is usually followed by a period of instruction, during which the neophyte is duly initiated by an old shaman. At this time the future shaman is supposed to master his mystical techniques and to learn the religious and mythological traditions of his tribe. Often, but not always, the preparatory stage culminates in a series of ceremonies that are commonly referred to as the initiation of the new shaman.’ But as Shirokogoroff rightly remarks in respect to the Tungus and the Manchu, we cannot properly speak of an initiation, since the candidates have actually been “initiated” long before their formal recognition by the master shamans and the community. Moreover, the same thing is true almost everywhere in Siberia and Central Asia; even where there is a public ceremony (e.g., among the Buryat ), it only confirms and validates the real ecstatic and secret initiation, which, as we saw, is the work of the spirits (sicknesses, dreams, etc.), completed by apprenticeship to a master shaman.
There is, however, a formal recognition by the master shamans. Among the Transbaikal Tungus a child is selected and brought up to be a shaman. After a certain amount of preparation he undergoes the first trials; he has to interpret dreams, demonstrate his ability in divination, and so on. The most dramatic moment comes when the candidate, in ecstasy, describes just what animals the spirits will send him so that he can make a costume from their pelts. Long afterward, when the animals have been hunted and the costume made, there is a new assembly; a reindeer is sacrificed to the dead shaman, the candidate puts on his costume and performs a “great shamanizing.”
Among the Tungus of Manchuria the process is somewhat different. The child is selected and taught, but it is his ecstatic capacity that determines his career. After the period of training described above comes the ceremony of “initiation” proper.
Two turn (trees of which the large branches have been cut off but whose crowns are preserved) are set up in front of a house.
These two turn are connected by cross beams, about 90 or 100 centimetres long, in an odd number, namely, 5, 7, or 9. A third turn is erected in a southern direction at the distance of several metres and connected with the eastern turd by a string, or narrow thong—s’Crim [“rope”] sup- plied at a distance of about thirty centimetres with bunches of ribbons and feathers of various birds. It may be made of Chinese red silk or of sinews coloured red. This is the “road” along which the spirits will move. On the strings a wooden ring is put that moves freely from one turii to another. When sent by the “teacher” the spirit is located in the plane of the ring (jreldu). Three wooden anthropomorphic placings—an’akan, of an unusually large size, about 30 centimetres long—are put near each turd. The candidate sits down between two turn, and drums. The old shaman calls one by one the spirits down the southern turn, and with the ring sends them to the candidate. Each time the teacher takes back the ring and sends off a spirit. If this were not done, the spirits would enter the candidate and would not leave him. . .
During the entering of the spirits the elders examine the candidate who . . must tell the whole history (“biography”) of the spirit, with all details, such as who it had been before, where it had lived ( in which “rivers” it had been), what it had done, with which shamans it had been and when the shamans had died .. . in order to convince the audience that the spirit is really in the candidate. . .. After every night of performance the shaman climbs up to the upper beam and remains there for some time. The costume is hung up on the beams of the turn. The ceremony continues for three, five, seven, or nine days. If the candidate succeeds, sacrifice is offered to the clan spirits.
Among the Manchu the public initiation ceremony formerly in- cluded the candidate’s walking over burning coals; if the apprentice had at his command the spirits that he claimed to possess, he could walk on fire without injury. Today the ceremony has become quite rare; it is said that the shamans’ powers have diminished,’ which is in harmony with the general North Asian idea of the present decadence of shamanism.
Takut, Samoyed, and Ostyak Initiations
According to the information collected by Ksenofontov from Yakut shamans, the master takes the novice’s soul on a long ec- static journey. They begin by climbing a mountain. From it the master shows the novice the forks in the road from which other paths ascend to the peaks; it is there that the sicknesses that harry men have their dwellings. After this the master takes his disciple into a house. There they don shamanic costumes and shamanize together. The master reveals to the novice how to recognize and cure the sicknesses that attack the various parts of the body. Each time that he names a part of the body, he spits in the disciple’s mouth, and the disciple must swallow the spittle so that he may know “the roads of the evils of Hell.” Finally the shaman takes his disciple to the upper world, among the celestial spirits. The shaman hence- forth possesses a “consecrated body” and can practice his profession.”
According to P. I. Tretyakov, the Samoyed and Ostyak of the Turukhansk region go about initiating the new shaman as follows: The candidate turns to face the west, and the master prays the Spirit of Darkness to help the novice and give him a guide. He then intones a hymn to the Spirit of Darkness, and the candidate repeats it. Finally come the ordeals that the Spirit inflicts on the novice, demanding his wife, his son, his goods, etc.”
Among the Goldi initiation takes place in public, as among the Tungus and the Buryat. The candidate’s family and numerous guests participate. There is singing and dancing ( there must be at least nine dancers), and nine pigs are sacrificed; the shamans drink their blood, go into ecstasy, and shamanize for a long time. The festival continues for several days 14 and becomes a sort of public celebration.
Ritual Tree Climbing
Ritually ascending a tree is a shamanic initiation rite in North America too. Among the Porno the ceremony for entrance into the secret societies lasts four days, one day being devoted entirely to the climbing of a tree-pole from twenty to thirty feet long and six inches in diameter.” It will be remembered that future Siberian shamans climb trees during or before their consecration. As we shall see,” the Vedic sacrificer also climbs a ritual post to reach heaven and the gods. Ascent by a tree, a liana, or a rope is an extremely widespread mythical motif.
To cite a final example: Initiation into the third and highest shamanic degree of the Sarawak manang 40 includes a ritual climb. A great jar is set on the veranda with two small ladders leaning against its sides. Facing each other, the two initiatory masters make the candidate climb up one of the ladders and down the other throughout a whole night. One of the first to observe this initiation, Archdeacon J. Perham, writing about 1885, admitted that he was unable to obtain any explanation of the rite.” Yet its meaning seems clear enough; it must represent a symbolic ascent to the sky followed by a return to earth. Similar rituals are found in Malekula; one of the higher degrees of the Maki initiation ceremony is called “ladder,” 42 and mounting a platform constitutes the essential act of the rite.” But this is not all. Shamans and medicine men, to say nothing of certain types of mystics, are able to fly like birds and perch on the branches of trees. The Hungarian shaman (taltos) “could jump up in a willow tree and sit on a branch that would have been too weak for a bird.
The experiences of Australian medicine men are no less inter- esting. They claim to possess a sort of magical rope with which they can climb to the tops of trees. “The doctor lies on his back under a tree, sends his cord up and climbs up on it to a nest on top of the tree, then across to other trees, and at sunset down to the tree again.” 47 According to the information collected by R. M. Berndt and A. P. Elkin, “a Wongaibon clever man, lying on his back at the foot of a tree, sent his cord directly up, and ‘climbed’ up with his head well back, body outstretched, legs apart, and arms to his sides. Arriving at the top, 40 feet up, he waved his arms to those below, and then came down in the same manner, and while still on his back the cord re-entered his body.”
Shamanism and Psychedelic Information Theory
The origins of shamanism are rooted in spirituality and myth, but the power of shamanism is entirely real. It is the goal of this text to explore rational limits and applications of shamanic power beyond the paradigms of mythology and faith healing. The subtitle of this text is “Shamanism in the Age of Reason,” so it seems fitting to provide a good definition for shamanism. There are many definitions that have something to do with tribal healers, witch doctors, ritual plant magic, and/or dealing with the spirit world; these definitions conjure images of pre-industrial folk medicine steeped in superstition. Relegating shamanism to the bin of folk medicine fails to account for the sophistication of shamanic tradecraft, methodology, or the varying levels of shamanic manipulation employed. Traditional shamanism may be cloaked in the veil of superstition, but behind the veil is the real science of programming human belief and behavior with a blend of mysticism, ritual, and psychedelic drugs. 
Instead of focusing on the many societal roles and functions a shaman might fill, PIT takes a broader view and starts with this definition: Shamanism is the craft of evoking spontaneous organization of psychedelic information in a subject or group of subjects to promote plasticity, imprinting, and transformation. Psychedelic information implies holistic or meta level manipulation of memory and identity, and so this definition fulfills the functions of therapy, sorcery, mind control, applied psychedelic science, targeted neuroplasticity, behavioral conditioning, and tribal bonding. The technology of evoking and imprinting psychedelic information is inherently neutral, the shaman learns to apply this technology for healing and positive plasticity, the sorcerer succumbs to the temptation to use this technology for black magic and negative plasticity.
Reference. Mircea Eliade; Shamanism: Archaic Techniques of Ecstasy . .Balzar, M. M. (2003). “Legacies of Fear: Religious Repression and Resilience in Siberia”. In Krippner, S.; McIntyre, T. M. (eds.). The Psychological Impact of War Trauma on Civilians: An International Perspective. Wesport, Connecticut: Praeger. pp. 256–267. . James L Kent , Psychedelic Information Theory : Shamanism in the Age of Reason.