How should I do the shadows on this hair?

[flat jewel]

i want to make the shadows of this hair and the face, but i dont know how to do it properly
(this is a redraw of a manga "Yofukashi no Uta")

this is the original manga part

[worldly cypress]

you could try using the panels that are already colored as refference, there's a few ones always in some chapters, assuming you want that

[loud hare]

Darker colour on multiple layer at top and end of bang. Large white highlights in middle of fringe

Use cell shading and sharp shapes