Retouching
My retouching skills development began in design school where I took advanced photoshop classes and every course on offer.
After graduation I took on freelance work until landing a role at The Real Real where I currently work as an in-house Senior Retoucher.
Frequency separation can be used to smooth skin in the even that a photo has so much detail that it brings the subjects pores out.
In the case the art director wants a shot the photographer didn't take and there was not time for a reshoot small alterations/composites can be made, i.e if the model had their mouth open for every shot and then after looking at the shoot decide they want one with it closed.
Following notes from the photographer I removed the light source, cleaned the image up, and color corrected it.