I turn myself around so my head is by the foot board. Changing positions help. If that doesn’t work – If I don’t fall asleep after 45 minutes, then I get up and read in the living room for like 30 minutes and try again.
I also used to think up crazy math problems in my head and try to solve them. It was so complex that I could think about anything else and fell asleep.
Shiurim also help you relax and clear your mind. I put my mp3 on very quiet and listen to it until I’m about to doze off.