Wow, Crimson Pearl! You definitely have a talent for art! These drawings are spectacular! I especially like the horse and Steampunk Navi~
The only advice that I can give you at this time is to practice your anatomy a little bit more.
Before making the final lineart, try drawing a light-lined, basic structure of your subject, complete with lines for the face. You can use a box-like approach for the body, or a more rounded approach. Actually, you can use any type of approach you want, as long as you make sure to indicate where the joints and are when you start your rough sketch~ Oh, and remember, you can keep erasing and adjusting the lines after you draw it; it doesn't have to be the final lines. Once you have the anatomy where it looks right, then try making the final lines for the lineart. It may seem like a hassle to do all of this, but trust me, it really, REALLY helps later on~ ^^
Wow, I hope that made enough sense... >.> Well, anyhoo, I hope that this quick advice helped you somehow!