I made some subtle revisions to this image to correct the overall symmetry. In reality, faces are not symmetrical, but ever still, there were areas on this portrait that needed tweaking in order to improve the overall likeness. One thing you can, and should, do as a digital painter is to periodically flip your entire image horizontally every so often. This will invariably show you parts of your image that don't look right. I did so here, and realized I needed to move one of the ears up and nudge the mouth over a bit to bring it more in line with the horizontal and vertical axes. I also went in and smoothed out the suit texture and added a bit of subtle texture to the skin to give it a punch of reality.