https://www.nma.art/videolessons/drawing-a-male-head-from-imagination/

In this video lesson, world-famous artist and instructor Glenn Vilppu demonstrates a rare master technique of drawing a realistic male head entirely from imagination. Glenn will discuss the major construction of the head and how to work into that framework, rendering with three colors, and creating a head and face with personality. You will also learn how the incidental details and solid drawing technique help create believability in the drawing.