the classic art

3 Flavors of Portrait Enhancement

Advanced Portrait Study

Dutch Angle Portraits

Portrait Theory "Get My Good Side"

I don't agreed totally with the theory.I think it depends on the face structure and the way that the face was present. Because if you don't have a certain structure to your face that the picture would turn out differently than other.
I would say that it work for almost all but when I take a picture of my face, the only angle that works for me was the center. My nose and face isn't as 3D. It's pretty flat so the only think that works is center because the side picture make me look flat face.

Double Exposure and Multiple Exposure Photography

Photo Stitch Process