http://www.sacred-magick.org/index.php?sho...73&hl=mushroomsIt's here.
For my part here, though I've said it elsewhere as well, I believe that the purpose of any entheogen is to help suspend the filtering and controlling mechanisms of the brain and show us another view of the world. Three or four times should be enough of any entheogen to begin learning to open your mind on your own.
Sometimes mystical visions to happen during these experiences, but even the most profound revelation should be taken with a sober attitude, not fanaticism.
The key to it, at least for me, is to fully engage the experience from beginning to end. "Follow" the path that the entheogen takes through your system, every little change, and try to burn it into your memory. Later I think we eventually can learn to just open our minds and go there, but in my own experience it is possible to retrace those footsteps psychosomatically. I have emulated Pot, Mushrooms, and Ecstacy. It is not as intense, because ultimately a part of you is in control whereas under the influence of a substance you are not. The first is simply deeply relaxing, the second creates a waking dreamlike state but with none of the random paranoia, emotional swinging, etc. The last actually tends to be a bit less tightly controlled in comparison, but cannot be sustained for very long, at least I can't sustain it, but it is a blissful experience that varies from time to time, sort of like the substance itself.
Mm, so that's my two cents on entheogens.
peace