Sometimes is hard to come up with a straight idea when it comes to choosing "The perfect Ink job". A reputable artist can help you decide, choose and also give you ideas in order to achieve what's desired so badly. The first thing the customer needs to do is to think or have an idea of what's wanted instead of simply walking to a shop and then choose whatever is on the wall.
It is best if the person chooses a design that has an actual meaning to them or something they relate to instead of choosing a design because it looks pretty or because was seeing on someone else. Always remember to be unique (as in custom work).
Something that also helps a lot is by choosing a few designs that can be altered a bit, have additional details added and make the project look outstanding but in harmony. It is good to find an artist that can pull it off and make it look like an actual entire piece instead of a few patches all over the place.