The easiest way to handle them is to starch and sew the sashing strip on prior to cutting off the points. if it's too late, I'd still try to starch, then stay stitch before putting on the sashing. Sew with the braid side against the feed dogs and the sashing up. Measure each piece in 1/4s and either mark with a pin or pencil and match up the 1/4s. Then pin in between those pins (lots of pins) should help hold it in place while you stitch. Looking forward to seeing it...I love French Braid quilts!