Sleep Hygiene. Retire & rise same time each day. Keep bedroom dark & cool & use only for sex & sleep. Turn off tv. No naps. Exercise regularly but not in late evening. No caffeine for 6 hrs & no alcohol or tobacco w/i 2 hrs of sleep. Keep dinner moderate sized & finish at least 2 to 3 hrs before sleep. Can try warm milk, chamomile tea or melatonin along w light reading, warm bath or lavender scent.
Good health. The only way to maintain health, including sleep, is by giving your cellular "engines" the right "fuel". Assuming that your genome is adequate, there is nothing else that you can do.
Behavior modifying. One place to start is practicing good sleep hygiene. Keep your sleep pattern consistently structured, avoid napping, use bed only for sleep or intimacy, and avoid lying in bed long periods without sleeping. If falling asleep is troublesome because of trouble turning off your thoughts, relaxation and imagery techniques are often helpful. For more help with these make an appointment with a therapist.