First, you need a card. I chose Monet's Waterlillies At Giverny sent to me by Alzheimer's Association. Thank you!
Next, cut your card in half on the fold line.
Next, choose which half will be the bottom of the box and cut 1/8" off 2 sides. This will allow the top of the box to fit nicely over the bottom.
Next, score 1" from the edge on all 4 sides of both pieces.
Next, clip the ends on the score lines.