To make someone look old in a drawing, focus on more than just wrinkles. Start by laying out the basic planes of the skull, like the eye sockets, nose, mouth, and cheekbones. Emphasize the cheekbones and how fat shifts with age, revealing more bone structure. Pay attention to how gravity affects facial fat, causing it to sag and create new contours. Use light and shadow to highlight these changes, and avoid over-relying on wrinkles, which can distract from the overall form.