When I first started quilting, way back in the 80's, I pressed my seams to one side. That was just the way it was done - also add the fact that I hand sewn all my quilts. Now fast forward a few decades, I now piece my quilts by machine and I discovered the challenges of making mini quilts. Making these minis was where I started to press my seams open. With pressing my seams open those mini blocks and quilts laid a lot flatter and there wasn't much bulk where seams came together. I liked how my seams were laying flat and the bulk at intersections were reduced. So mini quilt, up to a queen size quilt (that's the largest I will make) my seams are pressed open.