>>7647624
1. Don't paint too thick if you're gonna do contour
2. you can put light colors under dark but it is a lot harder to go the other way.
3. composition is very sensitive to implicit motion (like lines that don't line up).
4. Use references (plural)
5. paint is heavy
6. plants are harder to paint recognizably than animals
7. Prussian blue is somewhat like cerulean but the way they combine with whites is very different
8. Use a small brush, smaller brush, less paint on the brush if possible too.
9. mixing with a contaminated brush can ruin a color

Also some geography, and I'm not sure any of this is true but it is what I learned.