1. cut down time in bed. if you can't sleep, just get the fuck outta there. stay out until you feel sleepy, and wake up the next morning at the same time. eventually your body will get used to this routine and try to sleep in the time given. do some productive shit instead. 

2. don't try to fall asleep. the more you try and think about it, the less of a chance there is that you will actually sleep. instead, keep your mind on other things. meditate, let your mind wander, or read until you can't take it anymore. make sure you aren't wide awake after reading. just make sure to get up at the same time every morning (at least on weekdays).

3. make up some rituals. try: putting all schoolwork in your bag, choosing an outfit for the next day, read, do some homework, have a nice shower, etc. 

4. relax before going to bed.

5. keep a relatively normal sleeping schedule.