As an artist - especially a portrait artist - you have to become very familiar with the human skull. It is the foundation of the face. If you are ever going to accurately capture someone's likeness, you need to understand what lies beneath their skin.
batcii:had a few anons asking for tutorials lately and after trying to organise all the random half guides i’ve drawn up over the past few months into one tutorial i’ve just decided to clean up a few and post them separately. So he’s some really basic notes on constructing faces/proportions etc.