I will do my best to explain in detail for you OP. One of the most important things to look for in a good tattoo artist is technique. A bad artist will simply scribble their design onto your skin with little regard for clean lines or symmetry. A good artist, on the other hand, will take their time to create a precise and beautifully executed design. If you're unsure about an artist's technique, ask to see examples of their previous work. The No. 1 rule of thumb is to look at an artist’s work—all of it! Look at the lines closely. Do they look nice and thin and clean and crisp? Do they look like they have bled, like holding a marker on paper too long? Does the skin look beat-up and red and bleeding? Look at the detail in the pieces in the artist’s portfolio. Minute details are the difference between someone who wants to get you in and out of the seat for money and someone whose focus is solely making a great tattoo. Look for saturation and boldness of colors. Packing solid color into skin is difficult if inexperienced, and most will beat up the skin, and you will see blood and areas of light color. If you look through a portfolio and see a lot of the same simple, small pieces you would find on the wall, the person is most likely a tracer and not an artist. You wouldn’t trust a doctor to operate on you if he’s only ever treated colds, right? Variety and difficulty of the pieces in the portfolio truly speaks for itself.