One of the most common ways beginning writers show a character’s physical appearance involves posing the character in front of a mirror. This setup lends itself to a quick list of eye color, hair color, skin color, and face and body shape, which can be efficient, but it also risks being boring or cliché. More fun is invading a character’s body, like when Gaia moves through a tight tunnel, bracing her fingertips against the walls, I can give a sense of how that feels for her. She feels her hair warm against her cheek because she’s often hiding the scar on her face.
When she does finally encounter a mirror, she’s reluctant to look into it, which matches how she considers herself ugly. Of course, what matters about Gaia is what’s inside, where she’s strong and brave.