I know that Human skin is the ultimate holy grail of 3D art. It is so difficult and frustrating to master it, but I am doing that right now. As I have progressed further and further, I have now came to the point that I don’t know what to do next. It’s got SSS, Normal, Specular and all that. I have came to this result and I still don’t like it. I mean. I like the skin color, That’s the color that I really wanted to make, and it’s there, but still I am not convinced that it looks realistic enough. It some how gives away that fake feeling…
If somebody can give me a tip or what to do next, please, do so. I don’t know what to do now.
Your skin looks a bit too uniform, specially the glossy…
Normally, some parts of the skin are more reflective than others (foreheads, chicks, nose, lips); also there are different tonalities, different skin widths (i.e. head vs legs) and different roughnesses.
I think a slight variation of color/specular strenght/specular roughness could improve your shader.
Apart from that, your skin looks very good.
One thing to consider, also, is: “what sort of effect do you want?” In this shot, for example, “glossy skin” might be exactly what the lead-photographer on this (say … advertising shot for Vanity Fair magazine) would have worked very hard for. It’s entirely plausible that she would have deliberately used a shiny makeup, paying particular attention to such places as “the three places guys look at first” … the side of the face, the [inside of the] thighs, and especially, between the :eek:s.
(Her right :eek: looks spot-on, but the left one lacks some highlight and has some odd blackish lines around the edge.)
Right now, to me, what you’ve got looks pretty darned good: it makes the model look good. (As does the “chimpmunk eyes” mascara, the direct stare, and the slightly-open mouth.) The fact that she is presently bald makes her look even more exotic. The details of neck-area bones are good, and the fall of the cloth shirt is quite believable. (But you did forget the buttonholes, and you’ve got the buttons going through the wrong side of the cloth, as evidenced from the top portion near the neck, I think.) The use of contrast between the left and the right side of the head works very well, although I’d “juice up” that right-side shadow on her forehead by just a tiny amount so that it doesn’t go completely black. Do it in “post” is fine.)
A quick overlay of a BI render would eliminate the remaining “spottiness” from the Cycles-only render.
The skin, like everything else, should be: whatever serves the purposes of the shot. A girl (or, a guy) in an advertising photo is a fantasy that’s meant to make The Product look great. Don’t you want to order that combination Blender Tunic and Linen Shirt (only $225.00), because the girl surely comes with it? 
Thank you so mut! also, What do you mean by BI render? Should I replicate the model with different material or same material? Also, I have another question if you don’t mind, How do I make realistic white-shirt material?