You have some great coloring skill so far. I'd say, don't be afraid to use darker colors in areas to pump up the shading. And even though you are doing a Chibi style :) I suggest using
Posemaniacs.com for reference poses, and general movement.
Eyes can be tricky, because it all depends on what nationality you want to draw, and even more so different when you are trying to draw animals. my best suggestion for the eyes. is to look at all kinds of magazines and look at the different shapes. maybe take an old magazine and cut out different parts of the body to give you a better idea how human body shapes look. :)
Hope this was helpful.