That's a cute charicature face. And, a good lesson for someone who is already an artist who is expanding their skill set into digital cartooning.

I'm a portraitist and character artist and have tutored in drawing. While your system works for you, my experience is that most people need a simpler start, and a grounding in anatomy proportion. Drawing faces begins with deciding your proportions.

Without a comfortable understanding of proportions, most people will find it difficult to translate the lines they're making on an image into something cohesive for which they'll be proud. In other words, if they don't understand proportion, they won't be able to follow your directions to create a digital drawing of a face.

For faces, I found the simplest proportion tool was to have them picture an egg and transpose over it, in their mind's eye, their own face from the tip of their head to the tip of their chin. For bodies (unless it's for fashion illustration) I taught them the Greek model of proportion.