Hey!
To achieve realistic facial shading in an image, consider the following steps and techniques:
- Understand Light and Shadow- learn concepts like form and cast shadows.
- Observe Real Faces
- Start with Basic Shapes
- By Layering and Building up Shadows-Build up shadows gradually by layering darker tones. Start with a light layer and gradually increase the darkness, paying attention to the areas of the face that are recessed or receive less light. Use cross-hatching or other shading techniques to create depth and texture.
- Study Skin Texture
- Refine and Blend
https://youtube.com/shorts/B9JtLpz1t9s?feature=share
https://youtu.be/W9pTY2AEUp4
Hope this answered your question :D