Those sketches you keep posting are great! You really have a hand for accurate/realistic proportions and dynamic postures, which is refreshing to see for traditionally cartoonish characters like Pokemon. I'd even say it's better than the official art in many cases :P
Guess that proves that using simple geometric objects as a base helps regardless of skill level. I'll definitely try to utilize that more intensively myself, seeing as how it works wonders for your art.
When it comes to coloring your sketches, you could try giving hard shading / cel shading a shot. I believe that would complement your strong and expressive lines perfectly, and also emphasize your intuitive grasp of 3d shapes.
hngmn's thread is a great resource if your looking for inspiration. ^^
Btw, I love your choice of Pokemon. Keep up the good work!