Do you use gridding and work from a photograph? If so, do you take your own photographs? If you have the time, I would really appreciate a critique on my skull drawing and elder portrait, even though the elder portrait is far from finished. There seems to be something missing but.. I'm not entirely sure what. I may need to add in more shapes for photo realism and more contrast... I'm not sure. If you don't have the time, I completely understand. Thank you and stunning work.