I occasionally have a DILD where I become lucid pretty quick at the start of the dream, and it's due to that "feeling" you described 123north.

The other way I become lucid instantly is with a WILD. Basically I WBTB, then as I get drowsy enough, I feel/hear these odd vibrations, then a picture forms on my eyelids, then I "open" my eyes but I'm in a dream, already lucid. It's a seamless transition from awake to a lucid dream, so it's instant lucidity in that regard. But I'm not sure if that's what you were talking about.