In reply to Tall Clare:
Usually I'll get up, get something warm and caffiene-free to drink and maybe read for a bit and then go back off to sleep without too much hassle. Sometimes if I am awake for a while, I'll work on something. The wee hours of yesterday morning saw me drawing a flow chart for a program I need to write for some coursework. In that case, it was that piece of coursework that was bothering me, so doing something productive about it was helpful. I do try to stay away from backlit screens, although I will read my Kindle.
If I were living on my own and not in a tenement, I might trying playing my flute or twanging on t'other half's guitar for a while, but at the moment that's not really an option.
I have been known to go out for a walk (with the camera if it's near to sunrise). I won't do that when my partner is onshore though, because he would worry if he woke up and I was gone.
I have also been known to have a 4am bath
Lastly, someone was joking about masturbation at the top of the thread. That does actually work for me, I will usually drop off very quickly afterwards. The problem is doing it without waking up anyone else who might be in the bed...unless of course they are willing to help out
Thankfully, all seems to be serene at the moment and I am sleeping quite well for the most part.