I've had the same issues as others with having trouble falling to sleep or sleeping well through the night. I've even talked to my doctor about it but mine told me that mature folks don't require as much sleep.
Anyway, what I do to help really works well for me. This is going to sound pretty dumb but when I'm having trouble sleeping I start recalling my last round of golf......and think of evey shot......the club I hit, yardage and score hole by hole. Very seldom do I get past 9 holes before I'm fast asleep.
The other thing I've done is actually recount a 100 mile bike ride and try to remember every turn. A real yawner there for sure-except for the screaming descents down very curvy terrain.