I sew together the pieces in a block with 1/4" and I sew the blocks toghter with 1/2" seams. I use a machine to sew the blocks togehter. This may be cheating. When I quilted the blocks, the machine sewn seams would stand up, by quilting 1/8" next to the seam line on both the right and left side of the machine seams, they would then lay flat. I know this is hard to explain on "paper".