Take one clean lid. Cut a photo into a circle that will fit inside the lip of the lid (or in lieu of a photo, an illustration cut from a greeting card or any other little piece of artwork you'd like), then glue it onto the lid using a hot glue gun (for quick results) or Aileen's Tacky Glue (if you don't mind waiting for the glue to dry and/or have a tendency to burn yourself using a hot glue gun, like someone I know). For this ornament, I used an adorable picture of my son's dog Allie wearing reindeer antlers. Soon, I'll have photos of my soon-to-be-born twin grandchildren that I will use, but for now Allie will have to do. (If you want to see a close-up, click the photo twice to enlarge it--it's really very cute!)
To hide the edges of the photo, glue faux pearls or plastic beads (you can find them at any craft store) around the border to look like a wreath. Then make a ribbon bow and attach that. To make the hanger, hot glue a loop of ribbon onto the back, and voila!
I know it's only May, but I think any time is a good time to make a Christmas ornament. And even if you're not in the mood now, you can start saving the lids to use later on.