Think about colors. For example, if you want to accentuate something that is green, you can make that color brighter by using a green filter, or darker by using an orange or red filter. The red color would look different this way too, by becoming darker with the green filter and brighter with the red, so there's a lot to think about. You can use blue, yellow, orange, red, and green filters for almost entirely different looks with the same tattoo.
This can be used to create or subdue contrast in your negative, based on what the colors of the tattoo itself is, as well as the subject's skin tone.

That has a far bigger impact on your results than your film choice. In combination with color filters you can also illuminate the subject in different colors for similar effect.

Of course, by altering exposure and film development time you change the negative contrast.