I suffered with insomnia when I was younger, I learned a technique which Im not sure exists out there, but it works for me. So say I have a whirlpool of things keeping me up, I try to isolate each one and identify what it is about them that is worrying me. So like lets take a short list of things so: a deadline, social issues, geometry problems, past stuff.

Once Ive identified what each thing is I can put them in like categories of importance and go over them, figure out what is bothering me about it so for example, deadlines. Say i have something due tomorrow, what can I do RIGHT now.. I can either get up and do it or I can accept its a problem that I cant fix right now because I have to sleep and file it away. I got through each thing filing it away. Sometimes they pop back out of their file but I just file them back away until I am left with an empty head.

The filing system takes a lot of work and practice, it used to take me hours to file things away, now I can pretty much do it within about 15mins so it does get easier.

I hope this helps, and if anyone else does this Id be interested to know because as of yet Ive met no others who do this.