Can someone explain the trick when using coupons at the grocery store to lower your bill a lot like you have heard of in the media?

Follow these steps:

Find the store you want to shop for grocery's at.

Find a magazine or newspaper with coupons for the store you've got in mind.

Cut the coupons for the items you wish to purchase.

Go to store.

Find products you want, ask an associate for assistance if you need help locating your groceries.

Take the groceries to the cashier, and hand the coupons to the cashier at any time.

Note: If you decide to use the self-check out aisle... scan each coupon at any time during the transaction with the barcode located on the coupon.

Done.