Practising my Concept Art - Face

I've not drawn/sketched in ages so it was really relaxing to do it.

I used a reference image to get the shape right. I'm thinking about painting the face in block colours with a bit of highlights and shadows.

I've started to add colour into the image. A friend gave me some useful advice where I should try it in greyscale then add colour over the top of it once the shading and highlights have been put in. (Going to give it a try) 

So I put colour into the picture (going to try the greyscale one in the future).  I've never painted by starting off blocking it in then adding detail so this was fun to do.