I can now show the update to my earlier head turn post, in which I was struggling to get the breakdowns looking right. The shape of the face was all wrong but I couldn't figure out what specifically to change so I decided to just start the pose from scratch. I did some research and found a head turn from Scott Petersen to use as reference. It's a really clear and well executed head turn that has a lot of character to it. 

I studied the structure of the face and the way it moves from frame to frame to figure out how my characters face would change. It was really difficult for me to try to see the face in a sort of three dimensional way but I ended up feeling very pleased with how it has turned out.  I also noticed that the right eyebrow leads the movement and I tried to incorporate that into my animation.  

The first image is the before drawing, which was really bad, and the following four are what replaced it. The structure just looks right and natural when still but when in motion becomes almost invisible which is great because the wrong drawing stuck out instantly.