My mate's favourite quote: flirtation - attention without intention. But he's practically a manwhore so, that's just an excuse.
Personally, I never DO flirt on "intention" with most people; just a lot of jokes. But, with a few other people I'll do it on complete purpose. A pretty good example going on now:
Me: Ahhh am a pervert
Him: We're ALL perverts :P
Me: I blame you
Him: Just blame boys in general lol
Me: Permission there, or encouragement?
Him: Come to the dark side
Me: Can't you just tie me up and take me there?
He's one of the few people I casually flirt with, and have something of a history with so you know; it's okay x). When I've had a little alcohol I tend (like most people) to be more general in who I flirt with intentionally.
Recently licked one of my friend's cheeks (on the face, keep it clean people) who had come out of a two week "relationship" with someone he hasn't met, because I was in a happy-hyper mood. He found me to be too insensitive after what "he'd been through" and didn't even give me a christmas card xD I bought him SOCKS people. . .SOCKS and I get nothing because I gave him a lick under the mistletoe.
Really, sometimes flirting isn't as great as you think ;_;