Cheers for all the input, guys! Really is much appreciated
@GoldBlackWolf: I am aiming to make something pretty grim, dark, realistic(to an extent) and generally the stuff of nightmares. To this end, I wanted the eyes fairly small in comparison to the original Ghastly.
You'd be right, I think I did jump too quickly into higher subdivisions. Difficult not to do, but hopefully a habit that'll be broken with practice.
I have a general painting of how I wanted it to look, but I wanted to have a play with the contours of the skull, playing with ridges and recesses.
@Ockin: Aye, you would be correct with the membrane in the corners of the mouth, I've done as you said, and I have something that is looking pretty good there
I've filled in that 'double cheek bone' you highlighted in blue.
I'm yet to begin playing with the nose cavity and tongue, but once I rework those I'll post up some more pictures.