You will need a square of origami paper of 15 cm x 15cm
Fold the diagonals.
fold the edges inside and flatten.
Then, fold the edge against the fold.
Repeat on the other side.
repeat step 2 for the other side.
Flatten the base.
Put them on topof each other.
Fold the crners so it stays in place.
Do that for the other two corners.
You're box is completed