I just abandoned a quilt project that was all half-square triangles made from pre-cut 5" squares. I used the drawn line method and all was well until assembly took place and some points were off. Now if these were all the same size, is that supposed to happen? Is accuracy hard to achieve w/ these and if so, what do you do to maximize accuracy with those points? I read a little bit online and it seems many make them larger to start with and then later trim to size. Is that step i missed that would've yielded better results?