How to paint eyes

Paint the base color.

Paint a shadow over about two-thirds of the area.

Use black to highlight the edges of the shadow.

Brightly paint about half of the darkness in the middle.

Paint some of the area with a slightly brighter shade of a different color.

Add upward strokes from the edges of the shadow, keeping in mind the shape of the iris.

Add more of the same touches, as with step 5.

Add highlights and other details to finish.