I know there are a lot of preparation recipes for san pedro, but I have found only a few work well. My personal favorite method is also possibly the least complex. All you need to do is chop up the cactus (after removing the spines) into the star shaped pieces, then cut the flesh and skin away from the core. Then take these pieces and put them in some tupperware and freeze over night. You may also leave the core in if desired. Some say it does have some good alkaloids. The next morning you may want to let the pieces of cactus thaw a bit. Then place the pieces into the blender with an equal amount of water in height as the cactus in the container. So just fill the cantainer in the blender with enough water to barely cover the top of the cactus chunks. Mix well. Until it turns to mush or goo. Then take the goo and strain it through a cheese cloth or an old (but clean) t-shirt. At this point, if there was any goo leftover in the tupperware container after freezing, add it to the liquid after thawing it. This drink does taste nasty, but it is much better in my opinion than the boiling method. Try to drink it fairly quickly whithout gagging or throwing up. It shouldn't be too hard to keep down. Well thats about it. Drink it, and wait about two hours before noticing the effects. If you guys have any suggestions for improving this, or have a good recipe of your own, feel free to post it.