Ask to see the artist's tattoo portofolio
Do NOT be impressed by the flash on the wall. These illustrations are usually purchased from other artists and do not represent the work of your artist.
Frankly, anyone with some experience can easily trace the outlines of these illustrations and fill in the colors. What you really need to look at is a book that contains a collection of photos of the artist’s work.
Go to the counter and ask to see one. If they tell you they don’t have one, walk out immediately.
You’re visiting the shop to commission a piece of art to be permanently illustrated on your skin; for the artist to tell you s/he doesn’t have samples in a portfolio is insulting.
Keep in mind that anyone can stencil an outline of an illustration onto your skin. The skill in the artistry comes in the shading, use of colors and other subtle things that set an artist apart from a simple tattooist. Do you see anything in the portfolio that is not in the flash? These are the custom pieces that the artists have done, and they should be their crowning glory.
How do they look? Do you like what you see? If there is more than one artist working in the shop, and you see some photos you like, make sure to find out which artist did the work.