Start from top center, keep on stringing until B9 (skip A8 & A10). Go through B12, directly to A15, and then straight to A13, down to B10 and tie off at B8. (Opposite side the same procedure).
CROSSES
Make a knot at b6 and start crosses from b9. Keep on stringing until A8 (skip a11 & A9), then directly to a5 and tie off.