teen art landscapes

My teenage students are working on landscapes. I brought in photos of Wolf Kahn's and Milton Avery's work to inspire them. Concepts covered are horizon line, foreground, midground, background, and composition on the rectangular plane. After sketching in 4 horizontal lines to break up the canvas into sky, mountain, treeline/hedge, and grass/meadow, they are ready to begin adding paint. The assignment is to use "weird" colors, not what they think the sky/mountain/grass color "should be". Skills developed: trying styles of applying acrylic paint. Some are using wash techniques with lots of water, smoothing out with dry brush; others are letting brushstrokes show for texture. After completing these landscapes, some students may choose an option of adding trees, then perhaps interweaving something in the forest (Magritte's horsewoman, for example, or a dinosaur/dragon?). Others may redo a landscape, this time using more realistic colors. I find assigning odd colors (as in Avery and Kahn) helps students feel more relaxed about applying paint and they are not hung up with making it look "real" and "perfect".