1) Don't mirror copy the eyes and eyebrows, it will look unrealistic.
2) The eyebrows are the most unnatural looking part here. The shape in very artificial-looking, partially handled by drawing them separately (as in 1 above). Two colors would be also be better to have some kind of transition to the face color.
3) The red circle in the background is too strong a color, takes away from the face. You could delete the whole shape or just make it white instead of red.
4) Similarly, the shirt color pulls your attention away from the face. Tone it down.
5) Needs white highlights, in eyes, lips and teeth.
6) I don't understand the dark brown area in the hairline. Is it hair? A shadow? Either way, a very strange shape. Should be a way smoother shape. Or at least needs a whole separate shape to define the hairline.
7) The shading levels should be more even, in terms of change in value. Right now you have some shading that is very close to adjacent shades and then others that have a very radical value shift. They should be evened out.