I'm working on the neck now.
First make cross sections out of plexiglass.
Then fill them in and sculpt them to shape, in this case a combo of 15lb rigid foam and bondo.
Then vac form styrene over them so I have something to detail. I did this twice because of the layered details.
K'tinga Neck vacforming - YouTube
After that I can cut the parts out and start detailing them.
Psion, thanks for spotting that, sometimes I don't see mistakes until I take pics of it, LOL.