Draw only the lower part because the upper one is hidden under the hair.
Rias has a long, thick fringe.
Draw her haircut with the help of a semicircle.
They are big and round; that is typical for anime. Her eyebrows can be hardly visible under her fringe.
Draw a small nose and a nice mouth, mark her chin. Draw her curls.
Add a couple of curls on her hairdo beneath.
Add big eyeballs and pupils.
Draw Rias’s shoulders.