I am also contemplating this right now. I can't decide between my foot and my upper back/shoulder. It won't be a large one, but as a teacher I will need to be able to cover it up.

I have 4, one between the shoulders, one on each side of my color bone, and a big one that goes from my knee to my ankle, I think I gave up being able to "easily hide" a while ago. Good thing nurses have to wear scrubs