Drink coffee (maybe even decaf)
A cup of coffee contains anywhere from 80 to 120 milligrams of caffeine per cup, and you probably already know you should avoid it right before bed. But some still like the idea of a hot drink after dinner, says Grandner, and may not realize that although they're still several hours away from turning in, their habit could disturb sleep. Truth is, caffeine can stay in the body for up to 12 hours. "Even caffeine at lunch can be too close to bedtime for some people," says Grandner.