This is a quick and easy technique, and is quite fun once you get the hang of it.
The most annoying part of this instructable was getting the camera to fire on its own while I was in a good position. I couldn't get a good view of the cards actually shuffling, but this should be good enough. . . Right?
Step 1: Cut
This is your basic deck. It has a fine finish, has a nice checkerboard design, and was bought from a second hand store. This little deck can be used for a multitude of things -- from magic tricks to fending off boogeymen -- but the bridge is just a simple trick with the thumbs. So don't kill people with them -- shuffle the bridge.
Cut the deck in half. You do that by pulling one half of the deck with your other hand. WHOA! Easy, right? Next.
Step 2: Shuffle
Take your thumbs out of your pockets and shuffle the two ends. WHOA! Easy again! However, instead of smashing the cards together, you leave their edges sandwiched to do. . .
Step 3: The Bridge
Okay, so there's no more fun and easy things anymore, and no more of my futile attempts to make trashy jokes. This is very important -- put your thumbs side by side in the middle of the intersecting decks. If you can't do this, grow new thumbs. Push the whole deck up in a crescent shape -- retaining your thumbs position -- and let the cards drop into your fingers.
WHOA! That was easy! Or not. It took me two days of continuous repetition to get the hang of this, but with your more reputable skills, you can usurp my supremacy with ease. Well, that's about it. Thanks for reading, and remember -- Never forget your towel!