i watched a programme a while ago called something like '10 top tips to help you sleep' with kate silverton which was very interesting. the link here provides the ten things they suggested on the programme.
i'm not a good sleeper myself and have resorted to sleeping pills in the past. however, i've stopped worrying about it now and have found the pills work best when they're sitting inside my bedside drawer unused.
the tip i've found works best is not to go to bed or even try to sleep unless i'm really tired. sounds daft, but how often do you go to bed just because it's bedtime or your other half is ready for bed and you're not? so now i stay up later, read until my eyes close and my head nods, and get up at the same, relatively early time every morning regardless of how tired am or how comfy it is snuggled up in bed.
whilst all these tips aren't a cure, they most definately do help.
http://www.mayoclinic.com/health/sleep/HQ01387