This is an old video with no sound, new and improved version can be found here:
Portrait in GIMP 2.8 Part 1 Skin | http://youtu.be/yt3IKFnfRUo
Portrait in GIMP 2.8 Part 2 Eyes, Lips, Hair | http://youtu.be/AGOYw0mcK8Q
This is one of the ways you can use to retouch your portraits. I tried to do a gentle edit without turning my model into a doll. Usually I do more work on the entire photo, but it would stretch for another 30 minutes or so. I skipped the part where I was removing all the small blemishes to speed up the video.
If you have any questions regarding this tutorial, please ask 🙂
GIMP is a free software and it can be downloaded from here: http://www.gimp.org/
My text tutorials for GIMP 2.8 can be found here: http://dinablaszczak.hubpages.com/_ytb101/