How To Give A Tip To A Server

How should I give a tip to a server?

I like the money handshake. I've gotten a couple of those at the restaurant and I love it because it's a surprise. You open up your hand and, "what did I get?" One guy who was really sweet comes up to me after his meal, and he gives me a handshake and there's money in it. And later I looked at my hand and it was a dollar. But just put it in your hand and then shake it and they automatically know what it is. It's a pretty universal handshake.