Layer 2 fat quarters right sides together.
Draw a grid of squares on the lighter color fat quarter, making the grid be 1" larger than the size of HST you will need.
Draw diagonal lines through the grid so that each square has ONE diagonal line in it.
Sew 1'4" away from EACH side of EACH diagonal line.
Press the fat quarters after sewing.
Cut apart on EVERY DRAWN LINE.
Square up each HST.