Did you use topaz clean on her or something?
She seems liike..half painted.
Her shirt is much too bright. A curves layer with correct settings would fix that quick.
You said you needed practice with depth.
If you meant depth perception, than you should really work on your backrounds.
Whether you use your own effects, c4d's ,stock, w/e..anything will display it better than a black bg. Throwing good compositioned effects on a bg,
then messing with the perspective tool is also a pretty fun and great way to add depth.
Just be smart with you blur and sharpen layers/tools.