Let’s focus our sketches this time on the face of our characters. Having correct facial proportion and anatomy understanding is essential when it comes to animation.
Although you might have a great performance animated, if the audience is questioning the actual structure and placement of the facial features they are no longer paying attention to your story.
Work from constructing basic 3d shapes to ensure correct volume, and draw multiple views of the face from may angles. Also try to sketch from life as much as possible, if you can capture it quickly out in the world you can elaborate on the sketch later.
Progress to working with extreme shapes, with various styles. This exercise should produce some very interesting characters quickly, but remember the placement and proportions are key.
Cartoons follow their own guidelines on proportions based on what personality, age or style the character is being portrayed.
Drawing a Head From Imagination
Facial Proportions for Cartooning with Peter Emslie Parts 1 & 2