Making the skull

To make the back of the head a sphere was made and aligned to the reference images. It was then scaled to fit the reference images in both directions.

To get a consistent flow of geometry the number of segments was matched up with the existing geometry of the forehead. The sphere was then converted into an editable polygon so that it could be edited. The ploygons around the front of the face were removed and so were the ones around the ear so that they could be modelled at a later stage.

As the back of the head would eventually be attached to the front of the face, half of the sphere had to be removed.

The vertices were then aligned using snap toggle and the back of the head was attached to the face creating one editable shape.