I struggled with this one - painting over areas that became bogged down with too much detail (oh how I love to get lost in complex detail). Eventually I created a balance between areas of calm and areas of detail and now it's close to being finished. I'll work on the face when I'm back in the studio next month.
Sorry for the poor quality of the pic - it was taken at night, using the flash, and the reflected glare doesn't make for an accurate image.