Most time I quilt to the edge and so I do not have to fight this problem, But on those occasions that I do a QATG and do have loose edges, I either do a quick baste on the machine (usually at a looong stitch length) or if my serger has a thread color loaded that wont scream - I will square it up and serge the edges together (I use a long stitch here as well and I prefer one needle :the one that will give be the largest loops - but have been know to use two when I feel extremely lazy).