I started with my orange haired, blue skinned mermaid watercolor painting. Using levels, I created a couple of different color schemes. I used this blue hair, purple tailed version to remove the background & clean up the painting.
This part was a challenge for me, still being a newbie when it comes to working with layers, etc. I'm also using Affinity (which I'm also trying to learn ;) - instead of Photoshop. So, I was struggling a bit trying to use the instructions given to remove the background quickly.