Have you tried the obvious? No tea or coffee in the evening, smallish dinner but don't go to bed hungry. Milk, cheese or celery are supposed to be beneficial. You could try valerian or hops tablets. Don't watch telly right until bedtime.
If it is worry that keeps you awake, I can recommend the book "The power of now" by Eckhart Tolle. It is about living in the moment and not worrying about the past or future. It has helped me to sleep better.
"Think you can, think you can't; either way, you'll be right."-Henry Ford