Here's one EARTH MONTH idea I've been doing for a while: using large yogurt and cottage cheese lids repurposed as painting palettes for kids. They wash up great and you can reuse them over again.
I've never really realized how many items I repurpose so I can use them in an art project or for my kids' enjoyment.
As a much younger poor art student, I figured out in a hurry that art supplies are extremely expensive. One of my solutions: I used film metal canister lids for my oil painting palettes. I could close them and my paint wouldn't dry up. It was wonderful and free!
Ideas/items are all around us.
Reduce. Reuse. Recycle.