The Square Box is a traditional model that can actually function to store object inside. For safe keeping, however, it is recommended to make a second box as a lid.
The paper here is 15cm x 15cm, single-sided origami paper. Any paper cut into the shape of a square should be usable.
Fold the left edge over to meet the right edge. Crease then unfold.
Fold the top edge down to meet the bottom edge and crease.
Unfold.
Turn the paper over.
Fold the top right corner down to the bottom left corner. Crease then unfold.
Fold the top left corner down to the bottom right corner and crease.
Unfold.
Fold the top right and bottom left corners in to the center point.
Repeat with the top left and bottom right corners.
Fold the bottom right edge to meet the right diagonal center line.
fold the top left edge to meet the right diagonal center line.
Unfold Steps 11 and 12.
Unfold Step 10.
Fold the bottom left edge in to meet the left diagonal center line.
Fold the top right edge in to meet the left diagonal center line.
Unfold Steps 15 and 16.
Fold along the creases in Steps 15 and 16 to make them stand at 90°.
Fold the top left side up while using the previously made creases as guides.
Fold the top left side down over the other two sides of the box to make the top left wall.
Turn the model 180°.
Repeat Step 19.
Repeat Step 20. You have completed the Square Box.