Re: One more retouch for your valuable feedback
The biggest part that bothers me is the hair. You tried to chop it with very inconsistent lines, then tried to paint in flyaways. If you're going to paint in hair, it has to match in scale, sharpness, and overall color/tone. It also can't be all one color. You may have to refine it. I'll leave methods for another post. They aren't important right now. It starts with recognition. The hair is kind of crazy. You're not going to get clean and flowing from this. If you want to chop it, it should be consistent. You should be able to view it and tell me it works, not have something that looks like an almost arbitrary line due to separation around the outer parts and a sudden halt. Once again don't repaint flyaways like that. It looks like you just took a one pixel brush and tried to trace along the hair at 100% sharpness with a solid color. That doesn't work for anyone. The scale, sharpness, and variations have to match what was there in the beginning if you want to do that.
I think you should put some work into two areas before really trying to conquer those smaller details. The first is better determining what the mood of the final will be regardless of what image. The second to me would be better understanding of facial structure. There are areas where the color and things could be vastly improved, but it bothers me more how you made the jaw line overly angular compared to the original and essentially raised the cheekbone. These larger sensibility issues are going to hold you back much more than the smaller detail stuff. Both are important, but I think sensibility you should start with the broader aspects. I can see those at any resolution better than the smoothness of skin.