Usually if I have trouble sleeping (which I never really do) it's one of two things
1. Too much on my mind
2. Too much caffeine
Now there are many things you might wanna try, an overactive mind is usually due to too much stimulation before bedtime, try slowing down like half and hour before you wanna go to bed, try to avoid things like computer games or television, maybe try reading a book or having a nice hot bath. In short get yourself in the right mindset for going to sleep. If you still can't sleep it's pointless lying there worrying about not sleeping, get up for half an hour or sit up in bed and read a book again.
I tend to avoid anything with caffeine in it after 6pm, coffee, tea, coke, red bull. Caffeine is a stimulant and cause sleeplessness. Try replacing it with fruit juice or horlicks (dunno if you have that in the states but it's a malt drink)
If I still can't sleep i try thinking about the colour black, i find it comforting and it helps me slow my mind down. Try slowing your heartbeat too, breathe deeply and relax. Another technique to use is to check how comfy I am (if that makes sense) start at the toes and work my up checking each and every part of me is comfortable. If none of that works i try counting in my head, not sheep just counting it helps keep my brain focused on one thing instead of the thousands of thoughts swimming round in there.
So yeah after my essay
, I really think about sleeping a lot, I love to sleep, it's pretty much free (once the rents paid) and it passes the time quicker than anything else
. Just relax and try not to force it, fight through the tiredness in the day and you'll soon get back into the swing of things