When you observe a human face, you can see that it’s divided roughly into thirds from the hairline to the brow, the brow to the bottom of the nose (where it meets the very top of the philtrum), and the bottom of the nose to the bottom of the jaw. You can measure these distances on your own face and you will find them to be surprisingly similar. Dividing the face into these thirds is a great place to begin portrait drawing.
Remember, the hairline is not the top of the head. The very top of the cranium sits a little higher than the hairline. Also notice that, from the profile or side view, the ear begins at about the halfway point between the front of the forehead and the back of the head. A common mistake is to draw ears too far forward on the head. If you view them looking at the side of the head, you’ll see ears start halfway back and continue moving backward from there.