Here's how I do mine. I fold the quilt in half and lay the border right on top across the middle of the half (so it would be measured at the 1/4 and 3/4 of the top) and then cut the border as it lays on the quilt top. Saves measuring that way. Then I pin the side borders on starting with the middle, then the ends, then in between. Then sew. Then I press the border and lay it out again folded the other way and cut the top and bottom borders the same way. The borders always seem to lay flat.