Awhile ago, my husband and I purchased a few unpainted wooden train cars. They came in a Thomas the Train kit, but we really just wanted the pieces. On Valentine's Day, we decided to pull them out and paint them for a little family-bonding activity. The kids were thrilled. Since wooden train play takes up most of their waking hours, they were excited to make their very own cars. The little one chose the caboose and painted it his favorite color: blue. The bigger one chose the tank car and painted it his favorite color: green. My husband and I split the three boxcars. He painted one orange/silver and I went a little overboard with the other two. I wanted to create some unique cars that would appeal to the kids. It turns out that they fight over the pickle car so maybe I did too good of a job. It's fun to have some trains that nobody else has.
You can find this Thomas kit on Amazon for about $20. Or, if you're lucky, you can find them on ebay for a lot less. I just used cheap craft-store wood paints and covered them with clear varnish. I haven't painted anything in years and as funny as this little exercise was, it felt surprisingly good.