First I set my seam; it depends on the pattern and my quilting plans, whether I press open or to the side. If I'm pressing open, I do it from the back, opening the seam with my finger, then press again on the front with Best Press. If I'm pressing to the side, I do it from the front. If a pressed-to-the-side seam isn't lying flat, I'll press it on the back, too.