I had this adorable mouse already coloured in and cut out in my Christmas stash. I know it is from an old Peachy Keen set but not sure which one. The background is a Spellbinders die - large scallops. I used craft glue to adhere the card stock to the felt. I hand sewed the edges and lightly filled the inside of the ornament.
If you are wanting to have a new set of different, fun Christmas ornaments for your tree then using your stamps and felt shapes is the way to go. I would not think they would last until the next Christmas season but then new stamps will be out by then and you can create a whole new set of tree decorations.