Is there a certain technique used to spin cards while dealing? When watching the dealers, it doesn't look like they even flick their wrists.

It's called the "sail" and, while a professional croupier might get training on it, I believe it is mostly just a matter of practice. Most guys teaching gambling demos will encourage you to practice your techniques with a sail though they rarely get into detail. Not much to say really.

Not much technique to it. Assume you're dealing with the first finger and thumb, simply curl the second finger as you take the card and rapidly extend your second finger as you let go of the card. The card should 'sail' across the table. There isn't much wrist action involved, although if you're going to sail the card for a fair distance, then a wrist action would be helpful, though it is secondary.

If you deal with the second finger and thumb, simply use the third finger to "flick" the card. And so on and so forth.

Play with it, it shouldn't be hard to figure out the timing involved within a few minutes.

Cheers
Ted