In an effort to use every last drop of paint from these practically empty bottles:
I put a little bit of water in each one, shook it up and poured it into our paint tray (which is a muffin tin with applesauce cups stuck in it):
I found some simple Bob the Builder coloring pages online, printed them out and traced them onto regular printer paper with a white oil pastel crayon. I find that oil pastels work a bit better for this than regular wax crayons, but that is just my preference.
I put one paper in front of M, gave him some paintbrushes and he got busy. He loved the watercolors. I have to say, I think this worked so much better for us than the regular dry watercolors that you have to dip a wet brush in.
We did the same with two more pages (sorry no pictures!) and then he just painted on some papertowels: