I tire myself out in the day. Go running, cycle, get fresh air. It all helps and then I sleep much better. Have a good routine before bed and gradually your body will learn that when you do the routine it starts to get sleepy. My routine involves having a wash, getting into night clothes, having a hot drink and snack, going on the internet for about 30mins, then reading for about 30 mins. I often also listen to audiobooks when I'm going to sleep, but only ones I already know the story of very well otherwise I have to concentrate too much and I won't fall asleep.