If you're doing an all-over machine quilting pattern or meandering it might not matter which way you press your seams. Some teachers prefer if you plan out your pressing order before actually starting a quilt.....IF you plan to hand quilt, it's very important to make sure you've pressed carefully, so that you have the areas with only one layer of fabric where you plan to stitch. Stitching through a seam area by hand is not a fun thing.