I wanted to improve the look and depth of the effects in our games, I came across a very useful method of adding baked directional lighting into sprite sheets and using a shader to read this information, this works on particle systems as well as on regular meshes.

Above you can see one of the textures I used when testing out this effect. This method is called 6 way lighting and can be achieved via baking lighting information into the RGBA channels of two textures.

The first texture packing is:

the second textures channels are

This Shader-Graph shows how the setup works in Unity, I plan to move this across to HLSL when I use it in a production environment for performance gains. In this graph I have included custom functions to allow me to access the light direction and colour of a directional light.