I have been playing around with subway art recently. It is typically used in a frame, but I adjusted it to use on a card front. I made one with this freebie from the Todays Fabulous Finds website. Also, they had a teacher subway art here.
I was inspired by the teacher subway art to make one of my own. Here is a copy of the one I made. It isn't perfect, but I like the colors and am very happy at my first attempt. If you would like to use it, you may do so for personal use only. I hope you like it.