Remove the plastic, frame back and picture inserts from the picture frames.
If you don’t want the little tabs to show, you can pull them back and glue the glass to the frame or if it doesn’t bother you, then you can just put the tabs back down to hold the glass in place.
Glue the corners of the picture frames together. Hold together firmly until each frame dries (about a minute). Be generous with the glue because you want it to hold up well.
Trace and cut the outline of the box onto the cardboard or foam board.
Glue the foam board to the bottom of the box.
Pour some sand on the bottom of the lantern
Put you candle in the middle of the lantern
Arrange shells around the candle and add any other decorative accents you would like.