Consciousness is a fluid medium. We move in and out of various states of consciousness over the course of the day and our life times. Day dreaming at our desk at work is a form of altered state of consciousness. Every night as we sleep, we pass through several different states of consciousness. No one has enumerated all the various states, in part because they are subjective and difficult to pin down. We do know that certain techniques reliably produce shifts in consciousness. But much is unknown. Do we go to the same state when we chant versus when we drum, or take a drug versus meditate. So much of what is experienced seems dependent on cultural context, intention, and belief that it is difficult know. Still we know that the techniques listed below do predictably shift state of consciousness.
Sensory deprivation states
Group processes (dancing, singing, chanting)
Use of subtle energy
Most of these techniques (hypnosis, drugs, communal processes, drumming, sensory deprivation, and dreaming) are meant to create temporary shifts in state of consciousness. The experience is usually undertaken with a specific goal in mind – healing, gaining knowledge, or out of body travel. Meditation is the primary tool for achieving permanent shifts in consciousness.
Some would argue that communal processes and the cultivation of subtle energy states produce permanent transformation in consciousness; however, it is usually the case that at some point in their use, meditation is added if cultivation of permanent transformation is desired.