Handprints on canvases or just paint!
If you happen to have small canvases, use those, otherwise paper works well. Take some paint, acrylic or finger paint works best, and put small amounts around the canvas/paper and give the kids a brush. Tell them they can use their hands or their fingers and you want them to create a painting for you.
Mine decided to just use their hands and shmear it everywhere, and then I used their painted hands on a blank canvas where I put my own handprint and theirs overlapping mine. I’m going to probably write: "They add color into my world." over it in cursive.
Or take it up a notch and paint some piggy banks or other random things around the house that will entertain the kids! Crafts provoke curiosity and imagination, which is priceless.