Still moving crap and unpacking it, figured Id snap a quick pic how I do cartoony stuff.
Briefly I cast from an expandable foam and hollow out as needed, it is only good for front half, I add more foam for back half and to the cheeks and face as needed.

The pinkish thing is my silicone mother mold, the two white halfs on the bottom left are the backing that hold the mother mold when I do cast them.