I followed along with the 'Introduction to Character Modeling' course and this is my finished Pilot character.
I spent a lot of time sculpting the face and retopologising it faithfully.
One of the things that I noticed while retopologising the face was that the method used in this tutorial (where you place vertices on the surface of the sculpture) results in a model that has less prominent concave and convex forms than the sculpture. To get the retopologised model to match the sculpture, vertices in concave areas needed to be pushed below the surface of the sculpture and vertices in convex areas needed to be pulled above the surface of the sculpture.
Very impressive, I am on my third attempt at this exercise with no end in site.