I got into a routine. At 10:45 I sign off from IMing or hang up the phone, at 11:00 I brush my teeth, at 11:05 I lay out my clothes, at 11:10 I read for 20 minutes, at 11:30 I’m in bed. Of course, this changes a bit sometimes, but it’s a pretty usual pattern during the school week. Teens should set up whatever works for them, whatever will help them get good sleep time. The most important part is to enforce the routine every day until it becomes almost automatic.
I get a lot of exercise, but I try not to exercise within an hour of going to bed.
At night I try to do some things that will take my mind off school and other stressors. Your student could call a friend, talk online, watch TV, read a book, drink some herb tea—anything to relax the body and the mind.