Sculpting Louisa's head for Character Design

I am in the process of sculpting Louisa's head for use in character design sketches. I'm using Clayette, which is a type of oil based clay, quite soft and not sticky. She will then be moulded in silicone and cast a few times in resin and painted. This will allow me a 3d head reference which will help get angles correct in various poses for the character design. I came across this idea in this skillshare tutorial:

How to Draw the Head from Every Angle 


(you can get a free month trial of skillshare or currently 3 months for $0.99 so worth a look).