cord b right over left.
move both halves of cord a backward, then pass them under the crossed area of cord b.
pull both halves of each cord to tighten, after adjusting the size of the loop at the top (cord a).
turn the loop design upside down and secure it to your board (next image).
step 2: mentally label the four parts as if they were four separate cords.
move cord 4 to the left diagonally, passing over cords 2 and 3.
step 3: move cord 1 to the right diagonally, passing under cord 2, over cord 4, and under cord 3.
tighten by pulling on cords 1 and 4 while holding cords 2 and 3 