Try the following:
- Don't do anything apart form sleep in your bed. Well, ok, there is ONE other thing you can do. Reading's not it.
- Always go to sleep and get up at the same time
- Make sure your room is dark and cool
- Regular exercise is good for all of us, so you should be doing that anyway
- Don't eat heavy meals within three hours of going to bed
- Develop a bedtime routine; wind down properly
- Maybe change the position of your bed
- Some people find having their feet slightly higher than their head helps them sleep better
- If you still can't sleep, try paying attention to when you feel tired and when you are getting up, maybe you haven't got the right schedule for your body clock
- A lot of people I know need less sleep in the summer, as long as you feel rested, there's no problem with that
- Try yoga or any other relaxing exercise
- Keep a notebook by your bed, if you keep having the same recurring thoughts that stop you sleeping, write them down
- There are quite a few herbal remedies to be had and as far as I can judge, they work

Sleeping medication is ALWAYS just a short-term solution and the more often you take it, the worse your sleeping will get.