Not sure about legs(and everything else)

[darktiste]

The goal is to use line to describe what element is in front and what in the back. Bold line for close element and tinner line for distant element.
Bold line over overlapping element and it recommend to also outline the silhouette 
Use tinner line for the inside detail of an element

Thanks for reply! I then paint over with color in my artworks, but that is a valuable knowledge. I`ll fix it. What do you think about proportions?

I personally see them as small but it might be due to the foreshorting and low camera angle and the angled surface he is standing on.The feet attract to much attention because there the least detail element of the whole figure but it can be fixed but i believe it not a bad thing because the eye go from the bottom to the top of the figure.Also be aware that line inside an element can be use to direct the eye across the figure.For example i don't know if you see it but there an arrow in the design of you leg section.I added and image of the foot of a clone tropper i think drawing in the detail can help you check the proportion.

I also took the liberty to try to flip an element i believe didn't helped to direct the eye across the image.