Welcome to my chaotic brain which is evident in the way I sketch. I love using permanent materials for getting my concepts on paper, like paint, ink, and pens. The only times I really use pencils while sketching are when I have to make a detailed painting, or when I do a commission so it's clear for clients what they're getting.
I always make a million thumbnails. It's super helpful for wrapping my head around a concept. It doesn't have to be pretty or good, but it's amazing for visualizing ideas.
I love a spread like this. You can see my process in trying to figure out a character design, which you can see the final result of in the top left corner.