On to a nice start, a few things I would look at are the lips being a little to hard around the edges. The upper lip needs more volume so it merges better with the lip edge. The ears could do with some more forming. Pulling the upper lip out a bit with the nose will do wonders for it.
I would make the cranium little bigger. Just get as many refferences as you can and your start to see common patterns on all of them.
Kepp going at it as its looking nice so far, so basicly just work on more form at the moment.