1. Begin with the side panel and front panel, stopping sewing half inch from the bottom.
2. Do that on all those seams and the same on the base panel when you join that to the back panel.
3. When you come to join the two open gaps that Andrea always sticks her hands through in the videos you will line up the bottom of the side panel and the short end of the base panel nice and flat and the corner of the back or front panel will be squashed in between like a triangle shape. You just sew in a straight line making sure you catch that triangle piece and voila!