We’re taught that symmetry is the source of beauty, that the facing pages of the face must be identical. But the hand is unsteady and the skin is an imperfect palette, especially the fragile plane of the eyelid. YouTube videos can be helpful. Drag the point of the pencil or brush as close as possible to the edge of the lashes, explain a host of patient girls; extend a mark from the eye’s outer corner; connect the two lines to make a triangle; now fill the triangle in. But the tutorials can’t tell you what’s wrong with your face. Two inches from the mirror, all sense of scale vanishes. Your skin folds unevenly under the pressure of the pencil or brush. This lid is more hooded, that one less. The outer corner of one eye is slightly higher than the other. Is one whole eye higher? Should you respect the asymmetries or try to counteract them?

The truth is it doesn’t matter much. No one else looks at your face in a magnifying mirror, clinically or otherwise. You’re at a distance or in motion or already beloved. War paint, however applied, has a ceremonial purpose: to render the distinction between the everyday person and the warrior. Its application marks a transformation. These days I have the affect I wanted at 20: It takes zero effort to look tired. But I still like to draw a line between before and after, day and night. With a pencil and a simple black stroke, you can step out of youth and into experience, or out of hiding and into battle.