I had the chance to be a part of the 30 years UBISOFT anniversary convention by doing digital sculpting demo.
I sculpted each head from a sphere, blocking the major shapes and trying to not focus on details as much as possible. I spent 3 hours per head, based on photos references .
I did some 5 minutes timelapse to show my process.
more info: https://www.facebook.com/fabien.yorg/