Sorry, I can't teach this one, but I can direct you to a good teacher.
I struggle with faces, I have no clear idea where to begin and no clear understanding of the relationship of one part to another (OK, I get that your nose sticks out further, but that's not enough).
I found a Youtube poster who lays it out in an easy to understand logical order. She knows how to carve, and she knows how to teach. As shown, her little faces are excellent examples (In My Opinion) of Flat Plane work. Take a look at Sharon Elliot's channel, Sharon My Art on Youtube. Here are links to her Guide to Wood Carving Faces Parts 1 & 2:
Guide to Wood Carving Faces Parts 1
Guide to Wood Carving Faces Parts 2
I followed the steps as she did them the first time, now I'll just keep carving little faces and experimenting with changes and additional details to see what I can come up with.