Drawing I did for a Secret Santa event for Jargon Scott last year. A result of someone who has only ever drawn 3 busts, taking on a full scale artwork that would normally take around 2 weeks straight to make it presentable, for a very famous artist, with only 2.5 days to spare.  
So I did what I had to do. Drawing for 40 hours straight without doing anything else besides eating.
 
Uncut version. I did not like what I attempted with the lights it was cut. Submitted version is a downgrade but more stable and safe.