Yea I can help. I took your sprite and made same edits so I know how to help you out.
First, your eyes are far too complex. You have shadows under then that are giving it that off look. Look at the eyes of official sprites and you'll find that they are generally simple.
Secondly, for the way your head is tilted, the smile should be flat along where it is but curve up on our right not the left. You may also find that shortening the line will also give it a cleaner look.
Third, Shading. This is off on the entire sprite but you mentioned its your weakness. The light comes from the top left, so generally anything in the top left should automatically be lighter. For instance, you have a strand of brown shading on the yery tio thats giving it a blocky shape when zoomed out. Second example, you have the left (ours) arm in a darker shade (which is closest to the light) and a light shade in the bottom right (ours again) neer the belt (which is furthest from the light.
A tip for faces in general though, the shading should cross where the nose is and no other color is used to designate the nose.
Finally, make the eyebrow one color and shorten it to perhaps two pixels. Happy sprites generally have small eyebrows while serious ones have longer.
Hope I helped.
(Btw I cleaned up your sprite myself but didnt post it. If you want to see it for reference, send me a PM)
