Tip for immigrants to the Netherlands: check every time you're in an Albert Heijn if your shampoo, conditioner or toothpaste are on "1+1" sale (buy one get one free). Stock up when they're on this sale, avoid buying them at the normal, somewhat inflated price. (I also apply this rule to some packaged foods they sell that I like but just feel a little too expensive to justify as a routine grocery item, such as protein bars and instant macaroni cups.)
Also: if a perishable item at the Albert Heijn has a red barcode sticker on the FRONT, that's a clearance price because it's about to expire. If you want to buy it knowing you need to consume it quickly, be sure to scan the red barcode on the front and not the normal one on the back, it will save you a euro or two.