First, fold the paper in half diagonally and unfold.
Fold 2 opposite corners to the centre as shown.
Fold the back of the corners to the centre as shown.
Fold the bits you just folded up as shown.
Squish on sides corners in to touch the centre and fold up the back as shown.
Fold the back down and squash it to the back to create a wall as shown.
Repeat steps 5-6 on the other side.
Now you are finished. Make some use of it. It could hold your stationary.