I've heard of the finger through palm method, and the plug the nose method, but not the counting fingers method. It makes perfect sense.

You've heard about the looking at your hands method right? You just look at your hands, if they look funky then your dreaming. Whenever I've looked at my hands it looks like I've just eaten a ton of shrooms.

I really like methods like this, where you need nothing more than yourself, no text, no clocks, just hands. Sweet.