Something I've been doing with the self-adhesives, or "pressure sensitive adhesive" as the USPS likes to call it, is to pick up the scrap from the post office and cut borders around them of the backing. For those issues I can't get scrap, I'll use the majority of the stamps on the pane for postage and keep one or two to trim around. Here's a couple of examples:



I like the look of these and it keeps the stamp die cuts, which sometimes extend beyond the edge of the perforated backing paper protected.
Just my idea on the matter...