I could tell you about the methods that give me success, but it doesn't sound like that's quite what you're looking for. The bottom line is that, in most cases, the lucidity within my dreams is triggered when I start to get the feeling that something "just isn't right". Sometimes it relates to something specific that I can identify, like trying to shout and not being able to get out more than a hoarse whisper, but other times it's just a feeling. I know that sounds sort of vague, but hopefully you know what I mean. After the first time or two that it happens, even if you are only lucid for a few seconds, then you will know what I'm talking about.

Good luck, and keep trying. The only sure way to fail is to stop trying.

(BTW, the methods that usually work best for me are MILD & WBTB)