Just dropping in a few things I've messed with in Carrara: added a little bump (when there was no bump map in the texture) using mostly the cellular generator. Dialed down highlight quite a bit. Used soft shadows on lights (and plentiful GI). I think the anisotropic effects of "fake fresnel" shaders have much promise. I've tried slotting them in to alter highlights, bump depth, and tone -- usually by cloning the skin texture and making a mixer shader out of two variations of it (controlled by fake fresnel). So far, though, I'm not getting great skin in Carrara. But then, I've never gotten great skin in Poser, so I think it's me, not the program.