I've learn't how to draw faces not a master still need a whole lot of practice but getting there. I've learnt to draw them using the Loomis "Drawing heads and hands" as well a a few others to mix it all up a bit and get incite into other ways of doing it but Loomis was my main focus.

Now I am reasonably confident in drawing heads at a large A4 or A3 size id like to go smaller like you see in a illustration. While working digitally I can zoom in but id also like to be able to do it in pencil.

Is the key to not try to over detail the facial features? but to hint at the forms of the face? Any advice would be appreciated.