The easiest technique is DILD.... thats just realising your dreaming while dreaming.... You just have to get yourself into the right state of mind... Do reality checks but make SURE that you really question whether you dreaming or not.... Ive said it in another post. The best way is to assume you are dreaming until you prove otherwise with a reality check. My favourite reality check is the nose plug RC. Pinch your nostrils together and try to breathe through your nose. If you can your probably dreaming if not your awake.

All the info you need is on the site... Try yoshi's ADA tutorial too! Click here for ADA tutorial.

WILD is a harder technique to do. Try MILD too. And just so you know, they are all good techniques xD

Good luck.