From the way the aisles are laid out to sales displays, grocery stores employ a number of tricks to try to get you to buy and spend more.

But with some smart shopping behaviors, you can avoid overspending and spot the true bargains.

Bulk isn't always better: That big bag of avocados is often not any cheaper than buying the same amount by the pound, said Teri Gault, founder of The Grocery Game, a website that provides grocery price comparisons.

"We blindly think big bag, better value," she said. "That's not always the case."

Look high and low: While the center grocery shelves are considered prime market space, studies have shown that the highest and lowest shelves are often home to discounted or cheaper merchandise.

Be wary of 10 for $10 deals (and other deals like these): These common sales tactics may entice you to buy more jars of pickles or cans of tomatoes than you'll ever use. This is especially important to remember when you're dealing with perishable goods, like cheese or yogurt.

"Usually you don't have to buy all 10 to get the deal, but you think, 'maybe I can use more of these than I thought," said William Poundstone, author of "Priceless: The Myth of Fair Value and How to Take Advantage of It."

To spot the deepest discounts, look for sales that actually have a limit on the number of items you can purchase, said Gault.