Tip 3: Pore Structure

Pore Structure: Usually you don't want to sand blast someone's face. Real people have pores and you want to keep them as much as possible. In the highlights you may want to tone down pores that are very high contrast and prominent, but in other areas it's not as essential and can even create a plastic look. Take a look at the cheek of this model to see what I'm talking about when I say pore structure:

Before and After the first, basic retouching pass.

This is another photography vs. video thing. For photography maintaining the pore structure is more important than with video. With photography, viewers are staring at a single image so slight imperfections tend to be more noticable. Video moves at 30 frames a second and there's usually other distractions like audio or things moving. Viewers tend to be less critical of small details like pores, unless it's an extreme closeup. But, again, that doesn't mean you can try and sand blast a 50 year old to have 20 year old skin. Viewers absolutely will notice if the skin has NO detail and the eyes, hair, and lips have the usual amount of detail.