Mucking around before work (I really should be napping). Just an experiment with lighting. Brush used was the standard round brush with 100% opacity and 40% flow. Took around 1/2 hour.

Progress video: http://youtu.be/xW5mmyxWcHA

Sorry for my crappy video editing skills...I think the video speeds up for some reason but it's not hugely noticeable XD Also I went back and edited the pic a bit more once I finished the video, hence why there's more work done. Hope it helps people, anyway.