I had a few requests to post some step by step instructions for the blazing banyan tree, so here they are! I'll post the pictures, then below I'll post a few notes and tips. Please let me know if you try it and have success!
Step 1: Using a pencil on black paper, draw the tree trunk (make sure it isn't touching the bottom of the paper.)
Step 2: Extend the trunk lines to each side of the paper, to begin making your branches.
Step 3: Close up the lines to finish your first two branches
Step 4: Continue adding branches - 2 extending towards the sides of your page, and three extending up to the top of your page.
Step 5: Begin drawing bridges between your branches. Between every set of two branches, there should be two "bridges" coming out of them.
Step 6: Continue drawing the bridges between the branches. These are breaking your background into sections, which will help while you are coloring in.
Step 7: Add 2 branches extending from your side branches, towards the ground. Break these branches into 2 at the ends.
Step 8: Erase any lines that connect one branch to another. This will make your tree one fluid shape. Add a horizontal line to break up the background and the lake that the tree is coming out of. Finish off the bottom of your trunk with a slight curve.
Now, it's time to color! For each section you have created, you will use TWO colors of oil pastel to color in. You can assign rules for how to select color (cool colors only, one warm + one cool per section, analogous colors, etc.) I didn't put any limitations on it, as the focus of the lesson was on creating an object using negative space.
In the bottom portion, underneath the branches but before the lake, I let students color a gradient of colors, to create a sort of unnatural looking sunset.
Within an hour, you should have a great finished product!