General critiques for some drawings

Hi i just recently joined this site and ive been looking for some general feedback and critiques on some of my art. I dont have my own website but i do post most of my art (a lot of which is fan art) to my art blog here -->http://lib50.tumblr.com. Im really looking to improve my figure drawing abilities so any feedback would be very much appreciated!!!

Your art's great! Overall I would definitely recommend practicing anatomy, especially proportions; and I'd also suggest experimenting with using harder brushes in your paintings and doing away with airbrush altogether. Harder brushes create texture and will make your art more interesting to look at, and most beginners use airbrush because they're not confident in their skills, which holds them back from improving. Therefore, harder brushes are more visually appealing and create a bolder look, and you'll improve faster when using them because any mistakes will be more apparent and easier to pick out and adjust. Good luck with your future art!