Not all items are appropriate for this-sometimes it is much better to fill the bag up and let it go. Why all this emphasis about "build a wall" bagging all of a sudden?!? It's really being pushed in my store-tips on how to deal with it?
"Hey, maam, would you mind going back and doing some more shopping? I need you to buy several boxes of cereal (Wheaties, corn flakes, Cheerios, Lucky Charms, or whatever) and some good strong boxes of spaghetti and macaroni, because our baggers need more of those to build walls in your bags properly. Our managers will be happy if you do. Oh, btw please PLEASE don't come into my checkout lane with nothing but a pile of shapeless, formless bags of apples, oranges, tomatoes, birdseed, pinto beans and bagged salads, because we can't build very good walls with them! THANK YOU!! "