Sometimes the best way to capture hair is to look at the volume and capture the large value shapes.
It can be more striking than fussing would be. It can make real the cast shadows because of its suggested substance.
(Have you guessed yet? October is about hair. I get asked about hair all the time. I love sketching hair. Even if you don’t draw portraits of people, thinking about hair will help you draw fur, feathers, even shrubs. Get busy.)