I have the same problem.
Stuff I've tried (to greater or lesser effect) is:
Cutting all caffeine, or all caffeine a certain amount of time before bed (my current timing is midday for coffee and 2pm for tea- I usually go to bed at midnight. For most people that's extreme)
Only going to bed when you start to feel sleepy
Meditation or other relaxation techniques (aromatherapy, candles, etc. A massage if you can get it. I burn a candle with some lavender and have some lavender by my bed, to associate the smell with sleep)
Try to eliminate worries from your mind, including writing down the things you're worried about and leaving them until morning- there's nothing you can do about them now. Also perhaps leave a notebook by your bed and if thoughts are keeping you awake, write them down and try to clear them from your mind.
Warm bath/ shower before bed (but not too hot or close to bedtime or your body temperature will be too high. If you use aromatherapy, use the same scent in your bath. I use lavender bubble bath and light the room with just a couple of candles, and sometimes have to work hard not to fall asleep in the bath)
Bedtime routine- doing the same things at about the same time, or doing things that you only do when you're going to bed (I drink a herbal tea that's a "night time" blend, and I now associate it with sleep)
Sleep hygiene- doing as little as possible in your bedroom other than sleeping (e.g., no reading in bed, no television. I leave my bedroom for sleep, sex, and getting dressed)
Turning off computer, television and electronic devices at least half an hour before you intend to go to bed, and subdue the lighting before bedtime
Doing something completely relaxing (e.g. reading a trashy novel you don't have to think about) in the time before bed, help your brain switch off.
Don't clock watch- it'll keep you awake.
Don't stay in bed if you find yourself not heading towards sleep- get up and do something not stimulating in low light until you start to feel sleepy again. This is because you can set up a negative psychological cycle and associate your bed with insomnia, rather than sleep, which can exacerbate the insomnia.
Hope this gives you some new ideas to try.
