Of course don't stay up late (that's a given). I make it a rule to not stay up past 11:00 PM and try to go bed at around 10:00-10:30 PM. Don't use electronics right before going to bed. Make sure not too over-sleep because that can have negative effects too. If you have trouble to reach a deep sleep state, I'd suggest using a White Noise machine. Although it may be a little awkward using at first, it helps erase any noises that may distract me from my sleep.
Get exercise in the day, at night watch a movie,take a hot bath (shower works to), listen to your favorite radio station(as long as its not loud music),have all the lights turned off, get comfortable, and try to fall asleep, works every time for me. (the radio is supposed to stay on) also some people say drinking warm milk helps but I've never tried it