In this video I will show you a cool technique to build realistic 3d head from real photographs. You can either use a single photo or series of photos to model the head. Believe it or not there is no modeling going on this tutorial. Just install the free plugin, place the default head, add some markers(pins) and adjust. Voila.. you just made the head exactly the same as the photo.
Download the plugin before it become commercial : https://www.keentools.io/facebuilder (use the blender one)