17. Fold the left and right points of the front flaps to to meet the crease you made in the previous step.
18. Fold the top left and right points down to align with the middle point.
19. Open out the front right flap and slot the flap above it inside.
20. Repeat on the left side.
21. Flip the paper over to the other side.
22. Fold the left and right diagonal edges diagonally down to align with central vertical crease.
23. Fold the bottom left section diagonally outwards, making the top of the new flap a horizontal edge.
24. Flip the left section over to the right.