I would have to say that I like the Doctor's expressions the best in panels 2 and 3. They totally made me think of David.
I think I haven't missed him as much as everyone else (although he is one of my favorite Doctors) simply 'cause I'm making it my goal to watch every single Doctor Who ever made, so I'm still on Jon Pertwee. And since I don't have BBCA or a constant Internet, no new ones for me. *sad faces*
Thank you! I always do the basic head shape, like the ones you always see in 'how-to-draw' books. Then eyes, nose, mouth, SIDEBURNS. XD I'd really recommend this tutorial here for learning the basics: [link]