Another suggestion: Sketch out the pictures lightly first, and then darken the lines you want to keep and carefully erase the ones you don't. I find it helpful for getting the right shape (or close to it).

Coloring-wise, it would also be better to color it with more care, filling it in completely. And for stuff like the wings, you could color lightly to create a sort of transparent effect. 'Tis all about the smoothness.