I did another play on photoshop with my tablet:
This time I was using a bit of a different method, I drew the skull in rough at school (I had two real human skulls as a reference) and didn't plan on taking the drawing any further, just leaving it as a 2 min sketch. Then I decided to paint it so I scanned it in and painted underneath it (not over the top)
With the pencil overlayed on top:
Oh yeah, its also not finished, probably wont get finished either.. but that doesn't matter.

This time I was using a bit of a different method, I drew the skull in rough at school (I had two real human skulls as a reference) and didn't plan on taking the drawing any further, just leaving it as a 2 min sketch. Then I decided to paint it so I scanned it in and painted underneath it (not over the top)
With the pencil overlayed on top:

Oh yeah, its also not finished, probably wont get finished either.. but that doesn't matter.