Many ways to proceed with this image and no right or wrong.
I chose to increase contrast and let the areas of little interest go pure black or white.
Tighter crop and selectively sharpened her eyes and ring.
Because of the thoughtful expression, I thought that a slight blue tone would look good.

forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=25816735
original image by Jos4256: