Don't be shy, even if you don't have any tattoos yet. You'll be respected for taking tattooing so seriously. Also take into consideration the type of tattoo you want. Artists have their specialties, specific styles of tattooing that they excel at and love to do. Yes, a good tattooist can usually put on any style of tattoo you might desire and do a more than adequate job of it.
Some artists love to work in tones of black and gray, others have a wonderful sense of color.
Terrific tattoos are born when both artist and client are enthusiastic about the piece. That translates to mean that attitude counts. You have a right to have your important questions answered, and not to feel pressured into settling for a piece that's not quite right for you. On the other side, remember your artist is a business person and cannot devote hours to discussing a proposed piece with you. Most artists are happy to work with the client, if they know the client is serious about getting work.