Alright, let's see.
As for the first sprite, give the hair some outline. It looks too clumped up and vague in a way that it's difficult to recognize the portions of it. You'd also want to incorporate shading into your work at some point, as it generally makes your work more fleshed out, nice, and gives them depth. If you want tips on that you could contact me via PM or Showdown and I'd be very much privileged to teach you a few basics. Mostly, just decide where your light source is coming from and shade the parts opposite that source for consistency.
While I don't engage in spriting all tha