Cut out pictures you want to use on your gravestones. It is your project so you can use any photos you deem appropriate for the type of look you want to achieve on the gravestones.
Place a few drops of glue onto the back of your photos; add more if the photos are large, less if they are very small. Spread the glue around the back of the photo with a wooden craft stick or glue spreader.
Face the back of the photo, the side covered in glue, downward and place it on your tombstone where you want the photo displayed.
Repeat Steps 2 and 2 until your tombstone is covered in photos. Wipe off excess glue from the outsides of photos with a damp cloth.
Spray lacquer onto the tombstone when you are finished to "set" the photos. Lacquer can be purchased at any craft store or hardware store in spray paint form. It is best to spray paint laquer on your tombstones outside to keep it from covering your furniture, walls, floor or your children as they run by.