I can only sleep whenever it is dead quite. As an extremely light sleeper any small amount of noise wakes me up. Because of this I don't get much sleep.
I just get in bed and wait. It sometimes doesn't happen for a long time though. If I'm having a really hard time falling asleep I'll listen to Port Blue. My sleeping schedule is always messed up I'd normally be going to bed in an hour but I woke up like 3 hours ago so I'm going to have to adjust it back for work in a couple days.
I switch my aircon on (it runs year round), snuggle under the blankets, lay on my back with my my left leg slightly bent and my left arm resting on my stomach. I have a silk blanket that I've had since I was 2, I can't possibly sleep without it. I place it next to my face on my pillow so it's just touching my neck. I sleep this way everynight.