As a former seamstress, I like to press my seams open when I can, and I use a shorter stitch when I do it, so the seams don't pull open. I use a small iron to accomplish this, and to rearrange the seam meetings so they can lie flat as well. I do achieve better size consistency when I do this.
For the ones already done, I'd use an applique iron, to get into all those tight spots, and spray starch to make them crisp. For previously starched fabric, a light spritz of water will do nicely, and then use the iron.