Stores put a lot of thought into where products go. The shelves at eye level are prime territory, and they are often filled with well-known, higher-priced products. The items just above or below can be similar in quality and noticeably cheaper, yet they're easy to miss when you're moving quickly.

Make a habit of scanning the whole shelf before you choose. Look up toward the top shelves and down toward the bottom, where store brands and larger sizes are frequently placed. The same goes for end-of-aisle displays, which can feature items that aren't actually on sale even though the setup makes them look that way.

Checkout lanes work the same way, with candy, drinks and magazines placed right where you wait. None of this means you should never buy the product in front of you. It just means taking a few seconds to look around can help you find a better value without changing what you eat.