While your results may vary I find that when I have trouble sleeping I'll take a warm bath before going to bed and while laying in bed reading a book I'll drink a glass of warm milk.
Warm milk is a natural relaxant which helps some people drift off to sleep within 5 to 10 minutes.
For me I drift off to sleep within 5 minutes of finishing the glass of warm milk.
Also try going to bed at the same time each night so your bodies internal clock will adjust and help you drift off to sleep within the same time each night.