Measure the route, not just the basket
Picture the walk after checkout, including stairs, the bus transfer, and any other bag the shopper already has. A light but bulky pack may take both available hands, while a smaller bag of bottles adds most of the weight. Write the difficult items on the list before ordinary groceries fill the remaining space.
Sort the trip into carry-now and arrange-later
If a large item is necessary, make room for it deliberately. Buy paper goods on a separate trip or arrange delivery, then remove that item from the walking list. A discount loses its value if getting the purchase home becomes a separate problem.
Place one bulky purchase deliberately rather than squeezing it in at the end. If paper goods occupy the large bag, identify which vegetables fit in the second bag and which heavy items can wait. Decide whether a second trip, delivery, or another available shopper would genuinely be easier.
Adapt when the store changes the plan
A promotion may offer a larger package than you expected to carry. Check its actual size against the route before buying. If you decline it, keep the item open for another occasion and record the amount needed. A smaller bag carried comfortably today may suit the household better than a discount that requires an unplanned ride home.