Gather a square sheet of paper
Fold the paper in half both ways
Unfold the paper
Fold each corner toward the center
Fold the top and bottom edges toward the center
Unfold the top and bottom folds
Fold the left and right edges toward the center
Unfold the left and right folds
Lift two opposite sides along the creases
Fold the corner flaps inward to form the box walls
Repeat for the remaining sides
Press the edges to shape the box
Make a second identical piece for the lid if needed