I’m sure there are many out there who are not able to imagine the human head as a compound shape, e.g. a rounded plate attached to a sphere with its sides cut off, or a complicated construction. Why not simplify even more, and build a head out of that? It could be a good intermediate step.

A drawing of a man's head with annotations explains that a head is neither a block on a cylinder nor a cylinder on a block, questioning traditional construction methods.