It depends on if you're going back, and if you're happy with their work. I typically don't tip anyone (barber, for example), the first time I go to them. If you're building a relationship with them, $20 is a small price to pay. IF they take care of you. Aftercare, touch-ups, details, etc. My tattooist didn't value my time the first couple of times. "Two hours" for a job turned into four. That whole tattoo-shop time thing drives me nuts. Talked to him about it, and now I let him know when I go in how much time I have available. We get along, and he's a great artist. I value that. On the other hand, I hear the other artists all quote $100/ hour rates, which is crazy, BUT that hour typically turns into two or more, and for the original price they quoted you. After their fee spllits with the owner/ shop, sketch/ prep time, materials, etc, they're not making anywhere near that $100/hr. Like anything else, if I'm happy with the service, I'll tip. It doesn't appear to be expected by them, but they appreciate it. I think a lot of the shops are verrrrry slow right now. I don't tip my mechanic, though. And don't get me started on "tip" jars on fast food counters.