Besides set and setting, that is. I'm probably doing mushrooms soon, and I'm basically planning on hanging out at my friends house (who will be sober) either outside by his pond, or in his room, and listening to my iPod or something.
Look at a bad trip as an experience instead of something all horrible and negative, otherwise you will just perpetuate it if you happen to have one.
I find having to be confined somewhere very negative. I like the ability to journey wherever I want. So in other words no parents around.
After you eat them, spend the comeup doing pushups, pullups, lay on your back and stretch your legs over your head, and just generally tire yourself out, get healthy (it moves blood around and cleans your system a little bit) and take your attention away from the uncomfortable state of mind that occurs during the transition into trip mode. Other than that your on your own really. Good luck! Namaste