I usually line up my 12 1/2" ruler with both a side seam and a bottom seam to insure that I'm square. After I cut start my cuts..I use a long ruler and line part of it up with what I've alreay cut and then cut a little more. I do that all the way around the quilt.....but then come to think of it...I might be doing it wrong. :oops: :roll: Well, my quilts do lay flat and they usually end up square..so I guess it must be alright. :wink: