Put heavier items on the bottom. Put lighter items to the top. Don't crush the bread. Don't break the eggs.
Many of us are at least vaguely aware of these principles, but could use a go-to, step-by-step routine.

How to properly pack

Your Bag

Whether you’re a long-time toter of reusable bags, or a beginner looking to give it a try. You likely never had any instructions on packing bags efficiently. Use these tips to make the most of your bag space, speed yo your checkout time and arrive home with your groceries intact.
Uses spaces between other items for small things, like gum and batteries
Lay eggs and bread on top of the medium-weight bags and boxes
Stack medium-weight bags and boxes of rice, pasta and oatmeal of top of the cans
Put lighter, taller items like cereal boxes around the perimeter of the cans
Nestle glass items in the centre of the cans for support
Place cans in the bottom middle (no more than 6 cans per bag)
Pack heavier items first to keep the bag stable
When to bag the bag
Remember, not everything has to go in the grocery bags. Items that already have handles, like milk jugs, can be easier to carry without a bag. Large bags of dog food, soda fridge packs and jumbo cases of toilet paper can also be easier to carry separately, especially with adhesive carry handles.
It’s okay to forget your Reusable bag
Plastic grocery bags are still being sold but at a very small cost to you. In the even that you do forget your bag, don’t hesitate to purchase a bag and you can even reuse your plastic bags!