To be quite honest, during the week I sleep very little. I might sleep 4 or 5 hours on a normal school night. I find that when you need to sleep, or when your head tells you to sleep you find it even more difficult. I suffer from insomnia every now and then so I've gone through many many things in attempts to get myself to sleep. It's said that you should live out your day to it's full potential and get active throughout the day, then when you hit they hay you'll be tired enough just to drop off and fall asleep. Sometimes works, but I often felt over tired which led to restlessness and I got pretty grumpy too. So sometimes it doesn't work. Some other things would be to read in bed, relax before you sleep, rather than being on the computer a half hour before you go to sleep, turn it off and read or something. Having a warm glass of milk is nice too.
Oh, and I guess I use a normal blanket all year around to answer your question D: