I must say sometimes the piecing works out mighty nicely!
The trick is… Make sure you have an accurate quarter inch seam!
To test out your seam allowance:
Using scraps, cut 3 rectangles 2 1/2” wide x 6 1/2” long. Sew them together (on the long sides). Press & measure. The piece should measure 6 1/2” square. If it measures skinnier or wider than 6 1/2” (sewn width) adjust your seam.