Faust a dit:
Sometimes waking up in the middle of the night or early in the morning and going back to sleep helps. To me it seems to happen pretty random though.
WBTB technique (Wake Back To Bed)
There are multiple ways of attaining Lucid Dreams.
The most important one is to keep a log of your dreams.
Every morning try to remember them, in as much detail as possible.
When you wake up keep your eyes closed and if you have trouble remembering them, try remember the last thing you've dreamt about and then ask yourself:"What did I dream before this" and go back as much as possible.
Then when you remember the most, write them down.
Do this everyday, even when you've got just 2 or 3 sentences to put down.
This will enhance your memory.
Even if you have no LD's it is very important to keep track of your dreams.
That way you will get to know your DS's (Dreamsigns)
Things that make you realise you are dreaming.
So if you study your dreams you will get to know your DS's and are more likely to get LD's
There's a lot of techniques.
One of the most popular ones is the DILD technique (Dream Induced Lucid Dreaming)
For this technique it's important to do RC's (Reality Checks) preferably every hour. DILD's can be induced by constantly asking yourself if you are dreaming (RC's) and at one point you will do these RC's in your dreams, so that in your dream you will become aware that you are dreaming.
There is the WILD technique (Wake Induced Lucid Dreaming) but this is a hard one, since you'll have to fall asleep consciously.
(the one Braineater mentioned)
I suggest you check this topic on the Dreamviews Lucid Dreaming forum to read up on techniques and stuff
Lucid Dream Induction Techniques
Good luck!