The best thing is to get onto a regular sleep schedule. If you have to get up at 7am during the week, don't sleep in too late on the weekends. That way, you'll consistently start feeling tired at the "right" time.
Don't cram, cram, cram, then immediately try to sleep. Instead, take a half hour or so, to put your worries out of your mind before going to sleep. Have some hot chocolate, read a book, take a shower, whatever. (but don't wash your hair unless you want to blow dry it, otherwise your pillow will get soaked
)
If all else fails, morning coffee is your best friend
