20.Take a jar/glass/vase. Then take a box for freezing ice. Add food coloring (or paint) to the water, and freeze the colored cubes.
Buy the cheapest vegetable oil, pour it into a vase-jar, two-thirds. And throw cubes of colored ice there. You can sink ice cubes by holding them at the bottom with a spoon, you can cover the jar with a sieve and put ice in the sieve.
When inside there will be a picture – take a photo! Done! You are an eco-artist. Or a beginner ebru-artist… well, almost)
Submit your photo to the Munich Museum of Modern Art (or whatever museum you like)! Or to a photography contest. Or to your blog. Whatever do you think is more prestigious.

Now clean it all, what’s a mess…