Drinking alcohol a few hours before bedtime. Yes, a nightcap may help you sleep, but it can also interrupt that sleep later into the night and cause more trips to the bathroom.
Eating a few hours before bedtime. Lying down with a stomach full can promote heartburn, making it more difficult to fall asleep and get those hours in.
Consuming too much caffeine. The world works on caffeine, whether it be in coffee, tea, and sodas. Caffeine blocks a brain chemical called adenosine that promotes sleep.
Daily life stress. You'd be surprised how money, relationship problems, and work stress can affect your sleeping pattern. The more anxious you are about something during the day, the more you're going to think about it when you rest your head on that pillow come bedtime.