Great tips LP. The skin I used above was already desaturated directly via de-sating the texture maps, which could explain why it was a bit too white in the first place, but it looks good under normal lighting conditions.
As for ruddy skin, I almost always reduce the redness of Daz-store skins by increasing the SSS saturation value from pinkish to reddish.
Unless my monitor is out of whack I consistently find most skins far too red/tan for my liking.