Make sure you don't overexpose or underexpose your subject! Also, in this case, the edge of the table isn't doing a whole lot for me. IMHO it makes it look kind of home-made. If you were to get a tiny bit lower, the background would have been almost 100% black, and I think that would have looked a bit sharper. The lighting you used is pretty much overhead lighting, which usually gives a nice classy, elegant look to its subjects. Black backgrounds are also often used to create a nice classy, elegant look.
Keep shooting!
