Quick Self Portrait Study

One of my friends was going to sit for me, and I hadn't done one of these quick portraits in a while, so I decided to practice on myself. I didn't have much canvas lying around, so I just turned an old study I never finished upside down and just used the space.  I did this in less than 2 hours, with a very perfunctory drawing and then basically going in really quickly and building with color/value.