Here is another little trick.. use that iron to SET the stitiches before cutting. Also if your fabric is THIN or loosely wooven, don't be afraid to spray starch, iron then cut. It won't stop a couple of stitches from opening up, but that is NORMAL in strip piecing. The next stitch over (seam) will take care of that opening .... then the end quilting will help reinforce the "weak" areas. Just relax and see if MY GRANNY's advice works for you...