My mother had a technique for inducing sleep if she couldn’t find pleasant things to think of. She would get herself comfortable so that she knew she wouldn’t need to move. Then she would concentrate on her toes, wishing them to sleep.
When she felt they were totally relaxed, at rest and effectively asleep, she would concentrate on her insteps, then her heels, her ankles, each in turn until she felt they were ‘sleeping’. Then she would advance up the rest of her legs, her body, her fingers, hands and arms until she reached her shoulders, neck and head.
If at any time she was aware of any lower part coming awake again, she would start back down there, working her way back up her body parts. I have tried it a few times when I have had difficulty falling asleep naturally, and I must admit it really works for me. In fact, just writing the procedure down has made me feel very drowsy!
A Stuart Paterson, Bath