No caffeine after 10 AM helps me quite a bit. If you're a caffeinated pop or coffee drinker; try cutting back.
I try to avoid caffeine after 3 PM or so. If I go out for supper, I drink water or a beer or both. Before I started using CPAP, I could drink iced tea or soda anytime I wanted to and still fall asleep, (sometimes driving!) Now I don't take the chance of not being able to sleep and just stay away from caffeine beyond mid afternoon.
