The basic work shown in the after image can be achieved using several simple techniques. The tools you must master are: the layering option, the fade command and your airbrush. Take your original poser render and add a layer, use your lasso tool to select areas you want to brighten on your figure (example: look at the legs-following post work there is a whitish light flowing down the curves of the legs) Lasso inside the leg top to bottom, using a white pigment set your airbrush to 30-50% strength and lightly spray into the selected area-be as uniform as possible and don't over fill the area. Now select filter/ fade from your taskbar commands and slowly decrease the white pigment you just airbrushed in. As it fades you will have the same effect as the one you see-just keep practising this. The best results are when you learn to carefully select areas to hilight and learn to fade properly-the fade filter/effect/tool command combined with layers is the single most effective series of photoshop tools at your disposal. Remember to combine your layers. Then as pneal suggested above: use the curves command and add points at the top of the curves line segment and at the bottom of the line segment and move them to add weight and body to your skin tones. That's pretty much all you need to get the look you're after.