To draw hair effectively, follow these key steps:

1. Start by drawing the head and then establish the hairline, which shapes the forehead.
2. Sketch a rough outline of the hair volume around the head; hair should have space and not lie flat unless very thin or wet.
3. Determine the direction and flow of the hair strands based on hairstyle and gravity.
4. Use light strokes for initial outlines; darker strokes for defining locks and highlights.
5. Add shading and highlights to give hair realistic volume and texture, drawing strokes toward the light source.
6. For curly or textured hair, use circular or squiggly shapes to depict curls or waves.
7. Instead of drawing every single strand, think in terms of hair clumps or locks that wrap around the head contours.

It is useful to observe real hair references and practice with various pencil hardness to get different textures. Also, when shading, consider the light source to create natural highlights and shadows to enhance realism.