The ATCs are based on a set of the Twelve Days of Christmas ornaments I have. They are from the House of Hatten and designed by Denise Calla. My mom bought me several of them awhile back for Christmas when she was working at Miller Creek Folk Art gallery here in Holland. Sadly, that gallery closed and the ornaments are no longer made, so I've had to complete the set from purchases on Ebay.
I started by doing line drawings of each ornament and reducing them to ATC size (2 1/2 x 3 1/2). Then I copied them onto watercolor paper and painted them. Then I spray mounted them to a sheet of cover stock and cut them out. I put each one into a plastic protector and hole punched them in the corner. They are attached with colorful ball chain purchased from a hardware store with some colorful yarn.