Measure the jam jar lid to cover with paper. Glasses make great templates or use a circle cutter. This one is the Custom Cutting System from Creative Memories. I think it could probably be considered *vintage* but it still works great. You need two sheets of patterned paper. The polka dot paper is from Canvas Corp and the navy stars is from October Afternoon. The red and white gingham is from Martha Stewart. I made two sets of game pieces.
Use Modge Podge to adhere the paper to the lid.
Make a grid using washi tape (or duct tape would work well too).
Use a dot of hot glue on the back of each lid to secure a magnet. Pop into the frame and you're done.
Patriotic Tic Tac Toe!