On this video Aaron Nace from Phlearn demonstrates how to use one of the most powerful retouching techniques in Photoshop called frequency separation.
So what is frequency separation and why should you consider using it for retouching? well, frequency separation allows you to separate the texture of an image from the tone and color. In this way you can work on just the texture or the skin beneath it or just the color. This technique is useful for retouching (especially portraits) as you can work on all sorts of skin issues (redness for example) while leave the second layer to work on things such as wrinkles.
We have looked at frequency separation techniques many times in the past for including “Changing Makeup with Frequency Separation in Photoshop“, “How to Fix Shiny Skin in Photoshop” and “How to Retouch Lips Using Photoshop“.