OK, I found the original image, and I think I know what is throwing the image off. I didn't study art at school (Although I've taken a lot of casual classes), but I feel like in the process of focusing on the bumps and folds, you've lost the base form of the figure. I feel like using longer curves to map out her shape will help fix that. That, and looking at your negative space. The over all shape looks right- I just feel like there was a lot of focus put on detailing in contour rather than in shading.
Yes you're right. I think what happens is I get lazy when it comes to the shading. I don't want to take the time to do it. And I get sloppy. I also enjoy the contour portion because it seems the most interesting and in focusing on it too much, I lose the form.
Yeah- and using black and white to get highlights and shadows. It helps some people to work from a mid tone out. Forces you to focus on the whole range.
I hope that helped ^^;