If you have recurrent insomnia, I would suggest...
1. routine, go to sleep at the same time and definitely wake up at the same time everyday.
2. no tv, video, PC stimulation for at least 1 hour before sleep. The mental stimulation from the moving images can keep you up much later than you can imagine.
3. Die Happy's suggestion works
4. get laid, it will put you right out
5. I know you live in a northern latitude so I would also suggest you try getting some more sunlight (artificial or otherwise) in order to keep your circadian system "tricked" into a daily routine. One of those Lightbook products might be exactly what you need.
Biiviz,
i have had insomnia since I was like 14 years old and while it does come in handy sometimes, it can really bite you in the ass if you don't try to manage it well. I would recommend that you stop resorting to alcohol and if it is truly your only solution, go see your physician and make things right before you get yourself in trouble.
If this Insomnia only happens to you from time to time, then I would hazard that you have other issues that are causing stress and keeping you awake at night. If that is the case, "talk it out", "hug it out" or go see a therapist.
good luck man,