Quick notes for idanei

Been busy writing the Cliff notes and work.  Sorry for the late reply.  Good overall value.
I think it would be a good idea to spend time drawing the generic head and varying
your shapes from there.  That way you can gauge your proportions much better. 
Don't worry about any facial features.  You can achieve likeness much faster with hair shapes,
mask and skull.  ( Basically silhouette )   Your painting/drawing should work with just big planes
with a few medium shapes.  When all these are working, painting in an eye and adding facial features
are relatively easy.

Hope this helps.  Good job keep going !