Some rules I (try to) follow:
-don't do anything involving a screen past 7pm
-no caffeinated beverages after noon
-have a bedtime routine: get into jammies, brush teeth, have a cup of herbal tea, take meds, etc
-exercise during the day, but not after 6pm
-if you can't sleep, read something for half an hour to an hour and then try again
-listen to a podcast or a relaxing CD (there's one I have called Beethoven for Bedtime that I absolutely love, but I like listening to Stuff You Should Know (a podcast) as I'm going to bed too).
That's really all I have so far. Hopefully this helps and you can get some shuteye soon.