Here’s the little pochade box I used for all my little paintings while visiting New York. It fits 6” x 8” panels, and it’s made by Guerilla Painter. As you can see, it’s pretty small and basic, but the design is clever. The palette slides away to reveal storage space for paint tubes and such.
Using that box, I did this quick sketch of Red Caps at Penn Station while waiting for my train. Again, I had only the three primary colors to work with. The painting is not the greatest thing ever, but not bad for a quick thing from life. I did touch it up some on the train and at home, but most of the work was done on location, in about half an hour.