Exercise, by all means, but avoid heavy-duty exertion just before bedtime. They all upset sleep, even if they seem to be relaxing. Naps can make it hard to fall asleep later. If you're caffeine sensitive, don't consume it after 4 p.m. No alcohol after 7 p.m. Consult your doctor before taking sleeping pills, and don't take them for longer than a month. Don't eat a heavy meal before bedtime, but don't go to bed feeling hungry, either.
Light snacks are a sensible compromise.
Bedtime snacks, such as juice and cookies, can shorten the time one needs to fall asleep. Make your bed and bedroom a place reserved for sleep and sex only. No TV, reading, working, or anything else where you sleep. Create a relaxing bedtime ritual before turning in. Determine the room temperature that best helps you sleep, and maintain it all night.