I ususally start in the center and work out all four directions. and then alternate the direction of the stitching for the rest. That said- when using spray basting I do not think it really matters since the spray basting tends to hold the quilt top in place and it will not slide/move much during quilting. Also I just use my regular sewing foot when straight line stitching/SID. I can raise the pressfoot tension so I don't see much difference when not using the walking foot.