Staying up too late. By staying up too late you are liable to get a “second wind” which will make it difficult for you to fall asleep even if it is late.
Eating a large or heavy meal before bed. Heartburn, indigestion, and the need to urinate are counterproductive and end up disturbing your sleep.
Doing things other than sleeping in bed (watching TV, working, etc.). If you engage in activities other than sleep or sex in bed, your brain will cease to recognize cues indicating that the bed is the place for sleep.
Having caffeine before bed. Caffeine is a stimulant that keeps you awake.
Cigarette smoking. The nicotine found in cigarettes is a stimulant and will interfere with your body’s ability to fall asleep.
Exercising directly before bedtime. Exercise is healthy and can be very helpful if you do it several hours before going to sleep. Don’t exercise just before bedtime since the natural high ref: http://www.queendom.com/articles/mentalhealth/sleepguide.html produced from exercise will inhibit your ability to fall asleep immediately.
Forcing yourself to fall asleep. If you can’t fall asleep after 30 minutes, it is wise to get up and do something that is not stimulating. Forcing yourself to lie there will only frustrate you and take you even farther from your goal of sleep.
Daytime naps. Avoid daytime naps because they stagger your body’s biological rhythm. By taking naps, you might not be tired at bedtime and this will encourage you to stay up later. If you don’t go to bed at a reasonable hour, you might feel tired the next day and opt for another daytime nap, which establishes a vicious cycle. If napping is necessary, sleep for less than 1 hour before 3 pm.