Let's see. Most often I'll soft reset for shiny legendary pokemon on one of my NDS games - I just turn the volume way up and put it under my pillow, so my room stays dark and I can hear the sparkling noise if it's shiny. That normally puts me to sleep within about 10 minutes. I also have a playlist I listen to specifically for sleeping. Sometimes I'll read, or I'll just scribble on a piece of paper.
The most important thing is establishing a routine. Try googling sleep hygiene, that's what professionals will recommend before medication.
I also do something active first thing in the morning. I run for 20 minutes when I first get up - it's super healthy and it'll wake you up during the day, but by nighttime you'll be just a little bit more tired and ready to crash.
Hope this helps.

I turn on the fan. The sound of the fan is soothing to me and the cool air just makes me want to curl up in a blanket and go to sleep.

I read a book I don´t like.

Or I read paperwork.

I go to youtube and look for different sounds of nature videos. [link]
The sounds are really soothing to me, perfect for trying to relax. Then I just try to clear my mind of any bad thoughts or negative feelings and focus on sitting still. Eventually I slowly drift off to sleep.

I just stare at the internet and wait for it to do something interesting. Eventually, I just get bored enough to sleep.

I add a little to or read some/all of one of my stories and/or listen to calming music. If I really can't sleep then I go for a walk.

It depends on the reason. When I lost my marbles about 18 years ago, I tossed and turned all night and didn't really sleep more than an hour or two at a time for a month. If I have a cold and it's keeping me up -- which hasn't happened in a long time -- I just elevate my head slightly and try to sleep on my back.
And if it's not so traumatic, such as excitement about a big event, then I simply lie on my back, cross my arms on my chest, and listen to my slow, controlled breathing. If that doesn't work,I can recite a long poem to me. Anything that requires me to focus like that is good for a few zzzzz's

Listen to music.
Read a random book.

Don't ever think of something when you're trying to sleep! It only increases the insomnia.

Read Twilight. It'll put anyone to sleep.

Murder my neighbours, since they're the ones who've been keeping me awake these past two weeks.

Let my mind wander. it usually goes nowhere productive, and sometimes i just lay there thinking all sorts of random crap til my morning alarm goes off

Listen to random music on Last.FM

A nice, long, thought-provoking book that gives me some mental imagery to focus my thoughts around. Rushing thoughts are usually my insomnia-trigger.

Listen to music or read.

You don't wanna know

Listen to Ben Stine's voice. So monotone and boring. Like warm milk in the form of a voice.