I've had a lot of people curious about my colouring, so here you go!

Flats: Straightforward, just the flat colours. I do change some colours, making them lighter or more saturated but otherwise, just the plain colours.

Shading: Shading added! I do this differently all the time. I'm very found of Hard Light layers, other times I use multiply and sometimes I use the layer on lower opacity, which is what I did here.

Gradients: I chose this image to share since you can see what I do more. Generally, I add a pink hard or soft light gradient where light is coming from to lighten that area, then a purple for the darker areas. Here, I added those gradients and darkened around the image.

Textures: You can't really see this on a small image like this, but basically I add a neutral grey texture, it adds a paper texture without messing with my colours. I also sometimes, like here, add another texture that's coloured and have it on soft light/overlay.

If you have any questions, feel free to ask!