We did the same today for our brownies, using the variety of images of St. Martin of Tours from the heraldry site. We thought that they really looked like heraldry banners. There are many other saints in the coats of arms on the site. It would be a great place to look when you want to liven up a cupcake or other treat for a feast day.
Upcoming November saints that have images on the heraldry site:
St. Elizabeth of Hungary (November 17)
St. Catherine of Alexandria (November 25)
St. Andrew (November 30)