There’s a widely accepted shopping philosophy that you always need to buy bulk and jumbo-sized products to save the most. However, thanks to coupons, you'll have many opportunities to stockpile greater quantities of small containers for a better price than a few large items. For example, you might buy four 16-ounce jars of peanut butter instead of the big 64-ounce tub. You should still look at price per ounce, but when you add coupons into the mix it makes the smaller items cheaper. Here's an example:

Store Prices:
64 oz peanut butter is $8.97 ($0.14 per ounce)
16 oz peanut butter is $2.78 ($0.17 per ounce)

With a coupon for $1.00/1 peanut butter, look what happens to the price per ounce:

Final prices after coupon:
64 oz peanut butter now $7.97 after coupon ($0.125 per ounce)
16 oz peanut butter now $1.78 after coupon ($0.11 per ounce)

So if you want 128 ounces of peanut butter, you can buy two 64-ounce tubs for $15.94 or eight 16-ounce jars for $14.24—a savings of $1.70. This is especially propitious if you have a smaller household so you can ensure the product doesn’t go bad or dry out before it gets used up.

Remember, the best way to slash your grocery bill is to stockpile several of an item when it’s on sale and you have matching coupons!