Prep: - Movies, classical music, 60s music, dub, anything that you never had the patience before to hear or watch will spin you out (even if you never got into it), music you never understood (or could hear the words). A book or two, i know this sounds strange but either a book on Philosophy or quantum physics. You don't have to read it all whilst tripping but trust me a few sentances and your mind will spin off into out of space, and then just watch the conversation as you start going from one realisation to another.
Prep for comedown: warm bath (good for if your going to trip throughout the night, some valium or codiene (if you want to help turn off towards the end, and although most people like to trip during the night i for one start early during the day so when its time for bed time i'm starting to come down, also tripping during the day seeing the nature ats best is a sight to awe over....
I think finding the time to trip these days is probably the hardest thing...even harder then finding the damn stuff