Kinda sorta piggybacking on what Bopper said, sometimes it isn't about the lighting, skin tones, etc. It's about the scene. I've seen hundreds of otherwise very realistic and nearly exceptional renders in the gallery ruined by:

1. Not changing the default expression on the V4 model. A half smirk, half frown, pursed lips, etc would have SO changed the image and made it "realer".

2. Not changing the eyes. Eyes very very seldom ever look straight forward even if someone is staring straight at a camera. Move them two degrees up down or to either side and wow! You wouldn't believe the difference.

3. Feet! My biggest pet peeve. How many women do you know who walk around on tip toe while being naked and carrying a sword? Come on! Seriously!!

Now I'm only average and learning in terms of lighting and scale and texture; but I've produced some fairly passable results especially thanks to BB's VSS. But the MAIN thing that I think makes the scenes work is eyes, feet, expression, pose.

I'm sure I'm preaching to the choir, but I just REALLY wanted to gripe about feet today!!!