What are some questions to ask a tattoo artist to figure out if they know their stuff or not

Hi everyone,

As per title I am interested in getting to understand what to ask to a person in order to get some sense of what kind of knowledge of tattoos they have. For example if it's more about being a great visual artist or being knowledgeable about ink and/or different tools and what to do in certain situations etc...

I'm very curious to see what questions can come out from you!!