The best image adjustment for lighting or making skin paler over large surfaces in my mind is Variations (Image > Adjustments > Variations). It gives a true lighter hue effect that can be controlled at many levels. Others like the doge tool bleaches more than lightens - its good for small areas but hard to control well over larger areas. Brightness and Contrast is better than doge if you are going to print but it seems to gray out fine detail I feel it is really a tool for contrasting purposes only. Anywaylighten the layer to the desired effect. You now have the option of adjusting the blending options to soften, harden, overlay or what ever. The marble effect SamTherapy mentioned is a very good one, but you can also get interesting effects by creating 2 additional layer copies of your skin texture on top of your base texture. It gives it a look of different surface qualities that veins close to the upper surfaces. Step One: Is used as a base 100% blend - do not touch. Step Two: The middle skin texture layer. Apply first an Image > adjustments > hue/saturation (Hue=-4) or towards the red)) and save. Then apply a sponge effect. Go to the filter > artist > sponge (Brush size=2 Definition=12 Smoothness=5) and finish off with blur more filter - save. Now turn down the transparency blend to about 40%. Step Three: The top and finial layer which is the same as the base one - set the transparency layer blend to about 20% - or just as much as you need to just see the red sponge coming up through the surface. Merge down and save.