I found a cool painting on Pinterest from the Etsy shop that inspired this lesson with 6th graders. See it HERE. We spent some time looking at and talking about trees, how they grow, what they look like and then we proceeded to use black oil pastel to draw them. This was a great lesson to reinforce analogous colors on the color wheel. Using watercolors, they painted in the sections where the branches overlapped using analogous colors of paint. Red blends into orange, orange into yellow, yellow into green....you get the idea. The results were stunning!