My biggest pet peeve is when a client tries to talk over you and act like they know everything there is about a tattoo and the tattooing process because they watched x amount of seasons of tattoo oriented shows. That and Clients that insist that their tattoo is upside down or faces the wrong way for the position on the body.
- - - Updated - - -
Sometimes you just want to look at a client, cock your head and repeatedly shake the tattoo sense into them.