When I unload groceries onto the checkout belt, I put all the refrigerated and frozen items together, that "encourages" the bagger to put them together. All the heavy stuff goes on the belt first (detergent, juices, etc.), canned goods together, and chips/breads got on the belt LAST so they get put in bags together or on top of bags that still have a little room. Keeps bread from getting squished if nothing else. Seems to work