That used to be a very big problem of mine. I found myself thinking about random things that i done earlier in the day, and things that needed to be done the next day (ie. when i was under stress) and I couldn't get to sleep for hours on end. Im not going to say 'become less stressful' because thats not how it works. However i found that using a fan in my room helped me a lot in falling asleep, its not the coolness of it, its the sound of it . Apparently it helps to sooth your subconscious and works with white noise aswell ^^.

Also i've heard not using internal monologue whilst trying to sleep helps.

And this thread http://www.dreamviews.com/community/...ad.php?t=63951 talks a bit about helping you relax when falling asleep. They call it 'Self Hypnosis' but its just about relaxing. I've used some of the tips and they have helped me quite a bit.

Hope this helps you !