I like the idea of one color with various transparencies. Monotones. Thumbnail sketching is great because you get a creative boost and you could create patterns or hills of flowers. Ok these are obviously my ideas but there are countless ideas. Many times we wait until we have the “perfect idea”. Why not simply start?
Inexpensive suppllies like copy paper and tempera paint make it easier. I bought a tube of Royal and Langnicker white. Mixing time.