The first image is dull because her eyes are so emotionless, unfortunately.
Also, I'd advice you tweak and brush out some of her neck wrinkles, as she a tiny model, her neck placement seemed to have been poor. That comes with learning, I myself have a difficult time keeping my neck up, yet natural, especially when laying down.
Photo #2; I'd of slipped both nips, the idea of the jacket open on one side and not the other is a tad off. Rather than being artistic, it looks point of fact, sloppy. I'd also have tried her legs down rather than up, curled like that seems to make the model heavy in the tush...the lighting is far too bright as well, for her fair skin.
Photo #3; You have lost her eyes in her bangs. You never have a model look directly to the side/corner, her profile should be noticed, and the illusion of a straight on image be made. Also, the shadowing from the blue light, though creative seems to have overshadowed her corset (on the right)...Always think in small detail.
Photo #4: has too much white/background to the right of it. I personally would have preferred it cut down to size, unless the piece was to be used for editorial/article text or title.
Photo #5: She is lit to little on the left side. You want to make her a silhouette, not so invisible you can barely tell there is a person there (unless you open the image link). Side note; her arms/shoulders to her side look too stiff. That comes with model practice though
Photo #6: You cut off her forehead. That'd be okay if there was a little more to her head, but it just looks off putting at that crop. Again, slightly stiff arms/shoulders. Of the two, I would personally forgo the color image and keep it b&w in this case and concerning photo #5.
I know I was harsh and overly detailed in my critique, so let me ask..what do YOU want from your photography? If your ideal capture was in natural setting, natural stance, natural beauty...then your doing well. If you want to dig deeper and pull out that hidden grain of gold, with the concept(s) of choice, then you need to work on lighting, which will reduce your processing in your choice of photoshop material.
Also, placement when it comes to the models. Don't hesitate instructing the models, giving us ideas, showing us what to do/not to do we all like to get great images for our portfolio(s)!
Hope this helps you