I do it like QuiltingVagabond. Each row is pressed all in the same direction, then the next row is exactly opposite, so that the seams nest. In other words, Rows 1,3,5 and 7 are all pressed to the right, and Rows 2,4,6,8 are all pressed to the left. Then as the rows are sewn together everything fits. Even though you have a light background, with a white batting your seam allowances won't show much if at all.