I listen to music if the problem is that I've got too much on my mind to stop thinking. It drowns out distractions in my environment and provides a distraction from my thoughts. The rhythm and familiarity help lull me into sleep. If my problem is just that I'm over simulated I'll read something dense and meaty that takes a lot of thought to grasp. I'll get too tired from trying to think too hard while sleepy and that ultimately quiets my mind and body. I use Plato's Republic or contradictionsinthebible.com. I really love the latter when I'm awake enough to reflect on it, but at night it is a one way ticket to sleepyville. Plato's Republic put me to sleep every time I tried to read it for school because the arguments are very circular and repetitive in nature. I really wanted to like it but my mind said no.