Hair Cuts at Great Clips (or where ever) do you tip?

I always feel awkward when I go to pay after getting my hair buzzed off. I usually just hit up the local Great Clips when they have the "low wait time" sign hanging up front.

Give me a 1 on the side and a 3 on top. Blend it together and BAM... done. Nothing to it. I am in an out in just a few minuets.

I never know if I should give a tip or not when I go to pay. So... What do you guys do? Do you give a tip or not?