heres my crack at the lumis head it shows how i use the shell shape and when i break away from it also where i put the edges to match the face contours it might help. But don’t use mine for your project. It justs to help out not to be subbed in.
Your heads are coming along really well. I like the triangle head the only problem with that is you really need a vertical plane to paint your eyes on. Because the angle will sooner or later show the crease in the middle of them or the slope they are on.
http://mywebspace.wisc.edu/jgphillips/web/lumishead.blend (right click save targat as)