Step-by-step: Show a recognisable character ageing
I usually start with the middle stage, which is often adolescence. Consider thin, long limbs, dissatisfaction, a grumpy expression, as well as personal preferences in clothing as the character can afford to buy things for himself. From the adolescent stage, you can easily turn your character to a child or adult. When the character’s a child, eye shape and eyebrow thickness are about the same, but ear and nose size are altered. I don’t change his hairstyle, in favour of recognition. The character smiles and enjoys a care-free childhood. His parents buy him oversized clothes and he’s less concerned about his appearance. My teen becomes an adult. Shoulders and chest broaden, he’s taller, has shorter hair and facial proportions change subtly. My character wears a jacket and exudes confidence, but his pose exhibits frivolity from his teens. Glasses and beard might depict changes linked to age and status. But this character won’t like that!