Good retouching was supposed to do what proper Make Up and lighting would do.
In general lines, I use light retouching techniques. I never liked the idea of altering a photograph. And thus I don't change the body of my models, even if this is something very popular among other photographers.
To the very end, it is much better to try not do a mystake than fixing it later with computer software. Here are 4 characteristic cases where I use Image Retouching:
Skin retouching
In this example, lighting and Make Up wasn't very generous with Sabina...
But we see how a small enchantment on tones and skin retouching can transform the end result.
The thumb rule on here is to never remove permanent features of model's skin. For example, I would never remove a skar but temporary things like a bruise or mosquito bite.
Adding light
This example was from one of my first sessions, when I was unfarmiliar with this type of photography.
It is a fine case where a photo, clearly underexposed, was saved by retouching. As all can see, Anita in this photo is hardly visible. Her eyes and part of her face is barely visible.
Slowly and with patience, I had to light parts of this photograph. This of course added a lot of noise that had to later be removed with another circle of retouching.
Lesson to be learned: Better to be careful and NOT make the mystake rather than be careless and try fix things later.
Background removal
Many times, it happens that our scenere is limited. Just like in this case with Diana. The background had no symmetry, distracting the eyes away from her.
In some other cases, there were items in the background, totally unnecessary for the concept.
And even if those things can't always be removed on-set, it's nothing that a little retouching can't fix.
Using Presets
At this state, I rarely use preset as I prefer the image "as it". If you can say this for a digital photo of course...
However, when trying to achieve specific mood in the photo, presets are one-way and in this example with Diana, is clearly visible why.
The one used here is called "Cool Light" from Adobe Camera Raw.
Some presets can trully transform the end result of a hole session. So far I might apply it to a single image but haven't tryed that to a complete session. Perhaps in the future...