A sculpting process blocking in a head in 3DCoat by using simple shapes. The images show the brushes that I used while sculpting. The idea behind this is that it can be done in any other sculpting application. It's not about the brushes.
The secret to sculpting is all about using simple shapes. You can use these shapes to form a human skull and then flesh it out, or you can skip that step and use the shapes to form a base/foundation to sculpt on.