Then add colorful leaves by dotting the paper with the paintbrush. And fold the paper and press down again.
You can keep adding to the trees, just make sure you fold the paper now and then before the paint dries.
You don't want to push the paint around, just gently pat the paper so the painting transfers. We also painted a strip of grass along the crease to give a better visual of where the horizon was.
Then paint the bottom part (the water) but this time paint right on top of the trees, not just the white parts of the paper. This will smear it a bit, but it will look more like water. I encouraged the kids to use a little more water with their paint than they did for the sky. That makes it easier for the brush to glide over your trees.
P.S. To celebrate the letter C today, we had Crazy Hair Day! Here's a picture of a few of my kids: