Cleaning skin with Photoshop, use healing brush, clone stam tool and blur
The healing brush
This tool is very useful and handy to make up the skin. It takes care of keeping the skin structure interface automatically. It is works by selecting an area to copy structure form by ALT + Click. Then drawing over the area to "heal", you can try to clean up a few of the prominent skin features with it.
This is fairly easy, there's a lot of skin around. So the healing brush really is best solution. I revert to one of the other tools.
The Clone stamp tool
The clone stam simple duplicate a source area that you can define like a healing brush. You use ALT+click. As this make an exact copy of the source area.
You have to be careful in selecting the source area. Because it is easily to make it change the structure skin. The best thing is you should use it with the opacity of brush is lower than 50%
The Blur tool
This tool is make the skin is cleaner and softer. You should use it to tone down very small park of the skin. This is can be done after you use the healing brush or clone stamp tool
You use Brightness and contrast to make it lighter and more colorful
And the result:
Before:
After:
More Tutorials: 
