My favorite stress-relievers are
1. Exercise, particularly cardiovascular/aerobic workouts
2. Eating right and eating regularly. I often will forget to eat or let it slide, and I do better when I force myself to eat even before I let myself get hungry. Have a pencil sharpener metabolism, too.
3. Sex. It's another type of exercise, but there's nothing like cresting that peak to take care of your stress and that of your partner, too. Solo works fine, too, if you're single.
4. Drinking lots of water
5. Yoga. Try it. It's very relaxing.

I want to learn more about meditation to help me deal with school stress this year. The rest of those techniques above are tried-and-true favorites. The physical techniques like exercise, sex and yoga also help me alleviate depression, which I tend to get during the wintertime, without having to resort to prescribed medicines.