What difference can pressing a seam make? Believe it or not pressing is one of the major differences between a professional seamstress and beginner. When every seam is pressed it creates a smooth, almost invisible finished look. When they are not pressed you tend to notice all the seams more, they are bubbly and not flattering to the garment. I like to press all my seams open. This creates less bulk in the garment for a more comfortable wear.
You just have to make pressing a habit. It will become a sewing lifestyle that you cannot live without.