Hi Marion, have you ever tried using SCHOOL GLUE to baste the seams together before you sew them? Use just the smidgiest of smidgens of glue to just hold them in place so the feed dogs won't pull the lower fabric through faster than the top piece.
Also you can try using a leader and sew from the center out. Those small points can be tricky but I think the glue is the best bet to hold them in the right place as you sew.
Love these runners you are creating!
peace
Last edited by ube quilting; 01-17-2016 at 04:36 PM.