I find the general tips are quite good, like dark room, writing, reading, etc. There is also the possibility that you are so exhausted that your whole body just want to lay there and fall asleep, but you've reached a point where your mind just won't because the exhaustion. Sometimes you keep thinking about falling asleep and when you don't, you think about it even more; and that keeps you're brain active, then you get frustrated about it, and at that point, it is very very hard to fall asleep. Over the counter sleep aid, or prescription would help, even a painkiller would help to relax your mind. In my case a simple beer while watching tv before bed quiets my brain, but it rarely happens to me. Personally, light in my room does not bother my sleep, and tv on but very low volume or a fan turned on does not bother me as well, it blocks out the outside noise. Also it depends if you are a heavy or light sleeper, if you have insomnia or if it's just one of those nights. Most often than not, it's on our minds, I know people that drink a beer or take sleep aid every night after work because it "puts them to sleep", however, I think they have already influenced themselves into believing they "need it". Just try not to rely on "sleep aids" of any kind on a regular basis.