As a former art teacher, I learned that although direct sketching courses in the classroom were effective for a while, they had significant limits with bigger (and busier!) classrooms. Then there was the pace problem. Certain pupils have always desired to go at a quicker pace, while others want to travel at a slower pace. It contributed to the process seeming a little hectic, both for me and for them.
Take note of the muzzle's shape: Is the wire connecting it to the cranium flexible? Is the muzzle concave, convex, or flat? Is it long, thin, or thick? It is equally important to examine the ears. Are they separated by a great distance or by a little distance? Then consider if they are huge, pointed, or shaggy. Are they located on the crown or on the sides of the head?