Make a short list of things you buy again and again: soap, rice, detergent, batteries, toilet paper. When a genuine discount appears and you have room to store them, buy enough for the next stretch. Track the usual price for a month so you can tell a discount from a fake “was” price.
Do not stock perishable food you will throw away, and do not spend the cushion to “save” on a bulk buy. A discount financed by debt is not a discount.
Start this week
Pick three staples and write the price you usually pay. Buy extra only when you see a lower one.