I LOVE your paintings! My only suggestions would be for your graphite drawings:
1) Don't be afraid to go dark. Darks give depth. 2) Line quality. Work on being able to draw with continuous line (in other words, don't draw your lines with short dashes, lifting up frequently). At the same time, don't us line ALL the time. Sometimes the line disappears - like where the light hits on a 3/4 profile.
I don't know if you are using any books, but the ones I recommend are: "Drawing on the Right Side of the Brain" by Betty Edwards (without a doubt, the first book you should get), and "Figure Drawing: Design and Invention" by Michael Hampton. You might also want to check the Loomis books that are available online.
Keep drawing - looking forward to seeing what you'll create next!