Wow, okay. It's far harder to type out, but essentially it is 6 rectangles of cardboard cut to 9"x12". Label each rectangle 1 to 6. Placing them short edge top and long edge side in grid of 3 columns and 2 rows.
Rectangle 1 is in the upper left, rectangle 2 is in the upper middle, rectangle 3 is on the upper right.
Rectangle 4 is in the lower left, rectangle 5 is in the lower middle, rectangle 5 is on the lower right.
Rectangle 1's right long edge is taped to rectangle 2's long left edge.
Rectangle 2's right long edge is taped to rectangle 3's long left edge
Rectangle 1's lower short edge is taped to rectangle 4's upper short edge.
Rectangle 2's lower short edge is taped to rectangle 5's upper short edge
Rectangle 3's lower short edge is taped to rectangle 6's upper short edge
Rectangle 4, 5 and 6 are NOT taped to each other at all.
Place your shirt on the middle of the grid with the collar at the top in Rectangle 2. Adjust your shirt so you fold in the outer parts of the shirts to fit inside the grid. Fold Combo 1 and 3, then Fold in combo 3/6 and fold up 4.
Voila! Perfectly folded shirt.
If my instructions aren't clear, just let me know in the comments! <3 <3