the skin tone itself reall looks good, maybe it is also because of a clever lighting but yet the skin texture have to be very great too. but intimate parts (nipples and.. below) as well as face are not very convincing.... You need a bit more contrats i thing. A good exemple of nipple textures are the basic ones enclosd in Mayadoll (they are photorealistic and very high res), have a look to have clues about it. But it is a very very impressive first try, keep going on !

Are these your own findings or did you try the mat pose that was posted by dave on freestuff. I think it looks great but it looks there is too much ambience on the skin, EmpressZario suggested back on a thread that translucency didn't work well on some lighting environments http://www.renderosity.com/messages.ez?Form.ShowMessage=1373422 maybe try to tone down the lighting a bit. it's looking good keep working with it :)

thanks for the comments.. will try to tone the lighting down.. and increase the contrast...

my own experiment... after reading a few of the posts.. combining tranluncany and ambient light..

Excellent improvement I like how realistic the body looks around her breasts and legs, the face might need a few work are you applying your settings to her lips also?

much better.. now it is really impressive.