I'm no artist, my only qualification is that I like looking at nice art, so take my advice with a grain of salt ;)
Especially the first image looks flat overall. Be aware of the insides of a human, we've got bones, guts, muscle, tendons and more beneath our skin.
The trunk looks fine, however the neck and the left shoulder don't connect in a natural manner. The back of the neck isn't supposed to take that angle. It ought to connect to the torso's back, which contains the shoulder plates behind the thorax. See the red lines as indication of where it looks like her body is missing some important parts.
- 68quou6t.jpg (79.65 KiB) Viewed 12318 times
I apologize that I can't explain things better, I hope you still understand what I'm getting at. As for that little red line at the left side of her face, I just think it would be better to have that line curve a bit more, since, if you were to follow the straight line in your picture, the head would suddenly be deformed.
Also, the legs are too eh, plump? It's not at all wrong that the legs tend to be thicker than the arms, but think of it this way: when you look at a body from the side the upper leg would need be about the same diameter as the lower torso and get thinner from thereon. The legs don't match the body of the girl. Try taking away one third of them and see how it looks.
As I said, the torso itself looks fine, I also really like that subtle shading indicating the rip cage below her breasts and how you managed to draw the left hand. While not too detailed it's just enough to look good and convincing, although a bit messy.
What I enjoy most when looking at the girls are the eyes, though. They look great.
Your style overall is also rather nice. Still, you need to work more with shadows, especially in the second picture, to make your drawings look less flat.
I applaud that ^_^
