Like Keagaaan, I have a really messed up sleep cycle, due to a circadian rhythm disorder. In my case, I have non-24 hour sleep-wake disorder...My 'day' consists of about 26 hours or so, rather than 24, likely due to my body's need for extended sleep (which is apparently normal for fibromyalgia, according to my doctor). I tend to be more of a night owl, but my sleep cycle shifts regularly, going alongside my bipolar and other things to just make a complete confusing mess.
I have days where I don't sleep at all for over 24 hours just to stay awake for appointments, and then I crash for about eighteen or so. It's an endless, bad cycle that's a pain in the butt to work with.
For me...When I feel close to ready to going to bed, I take a shower. It helps me relax to the point that I get dizzy, which I find helps me fall asleep. If I'm having an off day, I may take a valium to calm down, but that's extremely rare. I currently sleep in a leather reclining chair because my room is horrible and not ready to live in, and my mattress is on the floor and I'm no longer comfortable that way like I used to be (right now, I don't have a bed frame that fits in my room). My grandmother will be giving me a bed soon, so I have to get my room cleaned up more so I can put the bed in in the next few months. Then it'll be easier on the one hand to sleep, since I have black out curtains there to help keep the light out and I can work better with the temperature. Like Kea, I sleep better in cooler temperatures. I tend to have night sweats even in colder temperatures, so...Yeah.
...I don't understand half of what I just wrote, but here's my recent sleep cycle.
In the past five days....
Day 1: Fell asleep 4AM, woke up at 5PM
Day 2: Fell asleep at 2AM (more than 24 hours later) or so; Woke up at 7PM
Day 3: Similar as above.
Day 4: Similar as above- woke up at 5PM
TODAY: Finally fell asleep at like 2PM and woke up at 4-5PM.
I'm all over the place.