Before you go to bed, stay standing up for a long time. Don't lean or sit for like an hour. Eventually your body will get really tired and it will help you fall asleep quicker. Sounds kinda weird but it works for me! If that doesn't work, then drink some warm milk before bed, listen to soothing music, and be in comfortable clothes. Don't text or watch tv right before bed, just focus on sleep, Hope I helped! Good luck! :)
Take a bath listen to some slow relaxing music clear your mind lay down close your eyes & breath deeply you'll fall asleep sooner or later unless you have a lot on your mind to much stress if so maybe you should try some NyQuil or Benadryl
Make sure you're not on your computer on watching television before going to bed and try to avoid any particularly stimulating activities because it will make it more difficult to sleep. I suggest doing activities that will make you more tired like perhaps excising or even just going for a quick walk. Other things that may work for you is something that is more calming like yoga or meditation. Warm liquids will most likely help as well but don't drink too much because you will find yourself waking up in the mid of the night to use the washroom.
Buy melatonin in the vitamin section at Walmart. It promotes sleep. I have insomnia and I take 6-9mgs and it puts me right to sleep(: it's a natural thing your brain produces for sleep and some people don't produce enough.