Start with a square sheet of paper
Fold the paper in half horizontally and crease
Unfold
Fold the paper in half vertically and crease
Unfold
Fold each corner into the center
Fold the top and bottom edges into the center
Unfold the top and bottom edges
Fold the left and right edges into the center
Unfold the left and right edges
Fold the top and bottom edges inward again to form the box sides
Lift the side flaps up
Tuck the corners inward to lock the shape
Press the folds firmly to shape the box