This is the way I sew cross hatching. First, I spray with Spray and Bond basting spray (purple and white can) on both sides between the flimsy, batting and backing. Pin about 8" apart. I use a walking foot and sew diagonal lines far apart first. Then I sew wide lines the opposite diagonal. Then I go back and sew the lines in-between. It helps to control the "creep" of diagonal sewing.