I refuse to combine layers out of fear of making mistakes (stray lines) and also hate deleting drafted sketches (so I can steal/reference them in the future). I usually don’t add color to artwork (but it would seem weird not to since OL is so colorful 😓) so most of it’s from me slowly figuring out that separating the base (flat?) colors from shading and rendering (with the remains of my mistakes floating around in the form of hidden layers)