Step-by-step: Laying out common Blending modes
1 Multiply is a fantastic tool at many stages of your process. Because white on a Multiply layer is omitted, it’s great for placing pencil scans into your piece to be coloured. It can be used for blocking in the initial shadows on colour flats, or for creating freckles or tattoos that interact with the skin tone of your character.
2 I find Overlay to be the most versatile Blending mode. When using lighter colours it creates a luminous glow, and darker colours can create rich shadows. It’s useful for blocking in your lights on colour flats, creating bloom and glow, pores and skin texture, and adding touches of saturated colour to the shadows’ edges.
3 Screen only adds lightness when applied. In addition, this light is more opaque and less saturated than what Overlay would create, which makes it ideal for creating atmosphere like fog or smoke. Layering in some soft Screen layers can also help push objects in your scene back in space, to create more realistic depth.