This was their first time using Brushes, so I introduced them to the layers and how they can help create a landscape showing correct proportion. We first created a black line drawing of mountains. Then added an additional layer to color in the background and moved the black line layer on top the colored layer to create a neatly outlined piece.
We repeated all these steps with the middle-ground of small cacti and then the foreground of larger cacti. Each piece was then downloaded to Dropbox.