Tinted Charcoal from Derwent

I have been experimenting with these Tinted Charcoal Pencils from Derwent lately. I have bought them after seeing some amazing work from Graham Brace and David Cook.

This is my second attempt with them:

It's still a bit weird to work with them, but they look like a great medium for sketching.

Derwent also has some great tips in their website on how to work with Tinted Charcoal:

http://www.pencils.co.uk/en/gb/4388/a/187093/tinted-charcoal-ten-top-tips