Zoo York and Reality's Flaw:

Hell, I wish I could pinpoint how I do it. Haha. It's a combination of things like the intensity of my dreams, how deep I'm asleep, my focus on staying lucid (or my lack thereof.) It's really hard to say what helps me stay lucid at different times. I know that I've been repeating to myself "I'm dreaming, I'm dreaming, I'm dreaming" in the back of my head, whenever I first realize I'm dreaming. It helps me to solidify that thought, and keeps my mind from wandering away from lucidity.
I didn't do that, in that dream, though, because the second I became lucid I started fighting, and the "bigger-than-life" action was enough to keep me from forgetting I was dreaming.

Of course, it doesn't work all the time, though. Every now and then, even though I've been LDing for years, I'll still wake up a second or two after realizing I'm dreaming. And yeah, it sucks as much, now, as it ever did.