be very careful to start your new stitches in the hole of one of the old stitches. carefully and slowly fill in the missing stitches until you come to a hole in the old stitching. on both ends, where you fill in, the new stitching should overlap the old stitching. at this point. some people thread a needle with the machine thread in the eye and pull it through the batting before cutting off, some tie off and some overlap enough that the stitching won't undo. you'll have to try and see what works for you. good luck.