These cards are super easy to make. Cut a sheet of card stock into 2 1/2 inch strips the length-wise. You should get three strips. Fold them in half and then into quarters.
Walgreens will print out 4×4 photos, so I used a photo app on my phone to make a four-panel photo that I had printed. I then cut them into 2×2 photos and glued them to the panels.
