Daughter just finished a queen sized Grandmother's Flower Garden quilt. I had found an old QUILT sampler magazine and the suggestion was to sew the straight seam on the every other side, which makes the center lie flat for as long as possible, as Patrice mentioned.
Back tack at the start and finish of each seam, stopping and starting 1/4" from the edge.
Then, the block was pressed, and then there were three U seams.
Forgive my brain .... I can't remember if the class had only one U seam and was grateful, but DD said that she enjoyed making the quilt following these instructions, so of course ... I just had to tell you what she said so you would have a choice <g> ...
It beats hand sewing, and you will find that you will KNOW the 1/4" seam allowance in time ... you will just FEEL it ... and, the funniest thing? It doesn't sound like a lot when you are first starting out, but soon, you will think 1/4"? That is as big as a HOUSE! lol
Well, maybe not as big as a house, but plenty accurate.