I thought that her feet/shoe had distracting perspective, so cropped tighter to eliminate.
Added a dark vignette to add to the moodiness and a little paint with light on the dress contours.
Softened the sky and distant trees a little with the blur tool.

forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=27612974
original image by digitalcounterculture: