Eh, give him a break.  Craigo probably gets dozens of e-mails a day asking how to do what he does.  And if he answers, it only leads to more questions, because the answers are not easy. 

Looking at his web site...I don't see how clothes are a problem, since his models don't seem to wear much of it.  ;-)

He may buy or make clothing especially designed to fit giganto-boobs.  Erotic/fetishwear is more likely to have the needed morphs built in.

The skin...there are various ways to make skin look more realistic using the Material Room, and you can also buy textures with a wet or sweaty look. 

As for the naughty bits, you can buy those, too.  Props or conforming genital figures that look more realistic. 

But looking at Craigo's work...it appears he does a lot of postwork.  At least, those don't look like renders straight out of Poser (if Poser is what he uses).  If you want to make images like his, learning Photoshop (or Gimp) is probably the way to go.