The other dynamics work with a tablet only
If you turn on opacity jitter, setting the control to "pen pressure", then the more you press with you tablet pen, the more opaque color you'll get. Flow is somewhat the same, you have to try them out to see the difference.
As for the desaturating: I'm not sure, I think I desaturated the reds just a bit. But for the lighting of the shirt, I used Amy Dressers' trick!

This is - when your retouching is complete, you set white as a foreground color. Then you go to select -> color range. This creates a selection. Then on a new layer, you fill that selection with white.
The High Pass filter - I apply it before the retouching starts. Just to make sure that after I think all retouching is complete the High Pass will not reveal some new blemish, as an example
