How do I find a good tattooist?

What should I look for?
What should I ask them?

The best way is to find someone whose tattoo you like, and ask them.

Failing this, you have to pound the pavement and visit each shop you’re interested in. The first thing you want to do is ask for their portfolio. Every tattoo artist who is proud of his work will have a big book of photos. Take a look at what he has done in the past and decide whether you like it.

Then ask to see him do a tattoo. Watch what he does and make sure you are okay with it. Check out his work area and make sure it is clean and sanitary. If the place looks like crap and he is not practicing good hygiene (like disinfecting surfaces, using gloves, etc) move on. Some states also require a license showing they’ve been trained in proper hygiene. This should be on display.

You can also ask what they specialize in. Some artists prefer a certain kind of work (tribal, Asian, etc).

Anybody who doesn’t want you to see his work area or look at his work doesn’t want your business. That means they’re ashamed of something. Asking lots of questions proves that you are a serious customer who expects high-quality art, rather than some drunk kid who wants Yosemite Sam on his ass. Trust me, the artist is going to put more effort into the former than the latter.