I used to suffer from insomnia and it is normally because you have things on your mind. Try not to watch TV or use the computer before you go to bed. Read a book - i know it sounds like a granny suggestion but i find myself falling asleep as I read and it really clears my mind.
The other thing is make sure you are not too hot as it is hard to fall asleep if your body is too hot. Try having a shower or bath before bed as that will relax you and get some lavender oil as the smell is very relaxing before bed.
There are also some very good non prescription sleep aids you can buy and some are natural
Good luck, i hope this helps!
