The best way of starting students with self portraits is to have them draw an oval and then paint the oval in a skin
color.
When the paint dries, students use conte or charcoal to draw in details of their eyes, nose and mouth.
I use the three division or thirds to get the proportions correct.
It is sometimes useful to use Mondrians Portraits as an example. Mondrian uses elongated ovals with long thin necks,
and yet gets a likeness.
Students like the freedom of charcoal and the skin color makes the face more realistic. Some great self portraits have
come out of this method.