Think of it as a hem on a dress…. you wouldn’t want the dress doubled. I make my pillow cases crossgrain, so they are 45″ long, a shirt hem and folded back inside on top of the pillow itself. I have nothing hangin off and the pillow end is covered, I like them that way best, especially since I pile them on top of the bedspread when I make the bed. I use a quilt for a bedspread and the pillow cases are made from two different county looking prints to match. As far as the width of any bands or trim, I would play around with whatever fabric you like, just making the bands not as wide as the folded hem. I like that part at least 3 or 4″ finished. All of the above is only my opinion, sewing is so much fun to create your own ideas and styles, just enjoy it. Betty_________________