Here are some general tips:
First, a pyramid profile, widest shelves at the bottom, lets the shopper see the most merchandise. Shelves with same width are best to mass display items the same size and shape.
Second, never place shelves so close together that the top shelf hides binned or boxed merchandise on the lower shelves. Shelves are for display and not for storage. And no top shelf should ever be wider than those below except on a sidewall or gondola over six feet high where the shelf is in fact more for storage than for display.
