I'm getting a better feel for using the lines as the core design element. Still not happy with everything, though. I like the eyes, but some of the contouring is just odd. I think the neck is the worst offender here. I think it is about the edges of the neck. I think the lines should make more of a sharp up turn and converge/overlap each other to create more depth. Stopping sharply at the edge makes it all look flat. I may pull up my Blender software and apply a line texture to a virtual model so I can check if I am correct.
I'm pretty sure I am.