Thanks, everyone! Appreciate all the comments and suggestions.
I was somewhat limited in what I could do at the time of shooting. The skulls were in a classroom. I had wanted to bring them home, but that was not possible. I used a black poster board and a few lights in the class, which were not the greatest, but at least I could move them around. And I used a white foamboard on an easel for a bounce. The entire setup was quite pathetic, lol, but you work with what you have, I suppose. I do like the idea of a vanitas type shot, and that may be something I will try for in the future.
Thanks again!