Take a close-up picture of the side of your neck that you want tattooed. Your shirt should be off, with your neck held at a natural angle, slightly extended.
Print several full-page versions of the photograph. Color will be best, but black and white works too if the tattoo will only be one color.
Decide what tattoo you want. This is a deeply personal decision. Is your passion music? Art? Do you prefer tribal designs or industrial ones? Are you getting a tattoo of a person's name or portrait? Will it be a religious tattoo? Remember, this is forever.
Sketch several versions of the tattoo on the printed photos with a pencil. Play with different sizes, angles and levels of detail.
Select your favorite few designs and do full color renderings in marker.
Select your favorite design and get inked.