Wow, rly like the detail on the armor plate for the 2nd one...even though u made it real simple...thts good...too much details can sometimes be a pain and look messy...
the first one could definetely be a sprite there, bud
seems like u got the shading done allright there...
though in the hair is too light maybe in some places it should be darker than others...
like in the middle of the hair the the other strands of hair come over the other side, should make a dark effect + behind...for the 2nd sprite there is barely shading for hair
u should make some outline of the hair...to make a shiney affect, using dark and light lines, tht makes the picture better when u have "breathing lines" makes it so much more...
(edit)
i think u understand "breathing lines" fine...cuz it shows as well....
but make sure not all ur outlines have simple dark outlines...