For me it would depend on the way I was going to quilt it. If I needed to put it on the longarm a certain way for the design to look right, then I would seam it so that the seams go across the length of the poles. If it doesn't matter how it is loaded on the frame, then it doesn't matter which directions the seam goes and I would do it the best way to use the least amount of fabric. Clear as mud???? I am sure everyone has their own way, this is just what I do.