hey,thanx for droppin by my sb.
i'll try to return the favour.
from what i see so far i can say you should probably stop shading for some time and return to pure lineart drawings. try to get your pics to look "3d" with lines only (meaning lineweight). i'm having trouble with that sometimes myself,but i'm working on it,and so should you. train your anatomy,and your line security. you're scribbling quite alot where you could draw one straight line. one way to solve that which i found recently is to simply draw in inks. using ink pens forces you to think carefully before laying down your strokes and it also helps you with seeing contrasts. although in this case i'd perhaps go back to anatomy books and lifedrawing abit more before going freehand. although you could try to draw with ink from anatomy books...hmm...i should attempt that myself.(EDIT: didn't browse thorougly,only saw page one,this stuff's alot better)
anyways, work on the basics abit more,so you know them more or less in-and-out. that way you'll have alot easier time with shading f.ex.
keep it up