I am comimg in a bit late on this but it follows from the discussion of opening the seams or not. If I am working on a block or just two pieces, I lay it down seam up. Hold one edge parallel to the seam and push the dry iron away from you, flattening the seam and not touching your fingers. If it is a very small piece, use just the tip of the iron. I usually turn it over and re press to make sure the seam is completely open on the top.
Mary