I've never had a professional haircut in my life, but I'm getting one today. When I was a kid, my sister would cut it, and since I was like twelve, I've had some pretty stupid punk haircuts that I would do myself or have a friend do because I felt stupid paying someone else to do it, and just lame. But... yeah... recently, I've changed my mind.
I know you're supposed to tip barbers, but how much? It's not a very fancy haircut at all, I'm not getting it styled or dyed or anything.