The nose and mouth stick out from the face, so light and shadow describe them better than outlines do. Start from the guide lines you placed in Proportions of the Head.
- The nose is like a wedge: a bridge, two sides, and a ball at the tip with the nostril wings beside it. With light from one side, one side of the wedge is in shadow, and there is a shadow under the tip.
- The nostril wings are about as far apart as the inner corners of the eyes, on an average face.
- The corners of the mouth line up roughly below the pupils.
- With light from above, the upper lip is usually darker than the lower lip, because it faces down, away from the light.
Key idea
Draw the nose with its planes and shadows, not a hard outline. The corners of the mouth line up roughly below the pupils.
Why it works
There is no line around a real nose. What you see are planes turning away from the light: the shadow side of the bridge, the dark nostrils, the shadow cast under the tip. Draw those and the nose stands out from the face. An outline says "flat cutout," and the nose looks pasted on.
Worked example: Where does the mouth go?
The bottom of the nose is 18 cm from the top of the head, and the chin is at 24 cm. Where does the mouth line go, and how wide is the mouth?
- The mouth sits about one third of the way from the nose to the chin: 6 ÷ 3 = 2, so about 20 cm from the top.
- Its corners line up roughly below the pupils.
Answer: About 20 cm from the top, with the corners below the pupils.
Common mistake
People outline the whole nose, both sides and the bottom, so it looks flat. Draw only the nostrils, the shadow under the tip and the shadow side, and leave the lit side open.