There are many things written on the subject. You may want to try different things that appeal to you then find what works amoungst those.
I have personally tried several things that work to regain lucidity.
Try rubbing your hands together. This has worked for me. It draws the conscious attention to the dream body. It's difficult the first few times
because the concentration all goes on "being awake in a dream" instead of the dream itself. So I guess pretty much anything that can quickly bring
your attention back to the dream will help.
Another thing I heard and tried successfully was spinning.

Not exactly, although it is a dream. But yea, stop and spin around about 10
times. It brings the conscious attentions to dream movement. I would say spin clockwise. By choosing and expressing a direction your awareness is
brought to the dream reality even more.
The obvious thing then is to spin clockwise 10x while rubbing your hands. This will bring your awareness to the dream body and dream movement
simultaneously. You will probably want to have something in mind to do immediately afterwards so you keep the dream awareness flowing. Like
flying.
I've finally figured out how to fly. Don't know if it will work for anyone else 'cus I never asked.
I run down a sloping hill as fast as I can (something around a 30-45° slope down). When I pick up plenty of speed I jump as high as I can and
remember there is no gravity. I land and notice I'm running faster. I wait a few seconds and jump again. This time it's higher and farther. I
land. Usually around the 3rd of 4th time I overcome my imagined dream gravity and start flying. This helps with the transition from waking laws to
dream laws. There actually are no dream laws but your mind uses the waking laws by default so you have to break your dream body out of it.
Hope that helps.
Edit: Oh yea, are you taking meletonin? Also, take vitamin B6. B6 helps you remember your dreams. Keeping a dream journal could help as well. The
more you remember your dreams in waking life and think about them the easier it is to become lucid in one because you will recognize certain things
more easily that will tip your mind off to the fact that your are dreaming.
You can also do little thinks in waking life that will help. Like say "if I was dreaming I could turn the lights off right now with my mind or my
hand could go through this wall". Basically, something you can't do in real life. After doing this for a bit, you will most likely dream you
doing it. And that can be used as a tip off for waking up in the dream. There's a bunch of other things. You can even look up OBE (out of body
experiences) and use some of the same techniques.
[Edited on 11-14-2004 by ShadowHasNoSource]