Shamanism is a spiritual path in which the shaman speak to spirits for guidance. They may be ancestral spirits, animal spirits, or even demigods. Shamans still exist today, and many offer their services online. Shamans often enter into an altered state in order to get in touch with spirits. While many of them may use natural drug or alcohol, there are other ways to induce a mind altering state without taking any substances. 

Deprivation: Vision quests, shamanic experiences in which one connects with the universe and learns about him or herself, may induce altered states through deprivation of some sort, whether it be sleep, food, water, or warmth. These deprivations cause the more rational part of the brain to shut down, allowing the more primitive side to express itself. 

Meditation: By coming to a place of extreme relaxation and focus, a person can tune in and be receptive to spirit world. The spirits are always talking to us; we may not hear them, but they speak to us. Meditation provides the stillness to open the mind.

Heightened emotion and sensation: often used in magick and spellcasting, heightened emotion and sensation focuses the mind, drawing and channeling energy. Like attracts like: anger emboldens angry spirits, while love empowers loving ones. Some energies, like sexual energy, can invigorate any type of magick.