From the Photography Forum
FAQ How do I get great-looking skin on a model? Start with a model with great skin, use a great makeup artist, and youâll cut down your retouching tremendously while getting better results. 
Once that's done...
Many retouching novices blur skin to achieve âcleanâ results. Unfortunately, to an educated eye, this is extremely obvious and unrealistic; blurring skin is virtually never a good idea for commercial or high-level work where realistic results are required.
In some portrait or glamour situations where the clients are less demanding and the time/cost tradeoffs are different, however, judicious blurring may be acceptable. In those cases use of the healing brush, clone tool, followed by a light application of a blur (Gaussian/median/anisotropic/etc) to the skin may be acceptable. Tools like the Skin Smoothing Plug-ins listed in lllâs lll's Photo Software List may save a little time over doing the blurring manually.
Angelo Lorenzo Photoâs thread Basic Pore Smoothing Technique gives a step-by-step description of an effective blur-based approach.
A more time-consuming approach, but one which gives far more realistic looking results is described in Ronald Tan's Basic Pixel Level Dodging and Burning Tutorial MM thread. Another thread describing this technique is Christosâ Understanding Skin Retouching Regarding LIGHT thread.
An offsite) guide from Glitterguru (Suzette Troche-Stapp) goes through this and more.
Also check out older threads on this topic. (Most of those discuss the less desirable blur-based techniques, however.)
