Lay out the panels in a grid of three wide by two high as shown in the picture. Space them out so that there is a gap of about 1/4 inch between each panel. This gap lets the panels easily fold and move while in use.
On both the front and back sides, tape each of the panels on the top row to each of the panels that are adjacent to it as shown in the picture. Then your shirt folding folding board is complete!