As the holiday-shopping silly season approaches, we share ways savvy consumers can save significantly. Here are summaries of the favorite shopping strategies of the editors at Twin Cities' Consumers' Checkbook and Checkbook.org, a nonprofit organization with a mission to help consumers get the best service and lowest prices.

Keep in mind that these are broad tips for getting deals. Checkbook finds the biggest mistake most consumers make is failing to comparison shop. To find the lowest-price stores and other advice for buying specific types of products and services, see Checkbook's articles and ratings. You can access Checkbook's ratings of local services for quality and price free of charge until Dec. 5 by using this link: www.checkbook.org/StarTribune/Save

Don't assume that a sale price is a good price. Checkbook's undercover shoppers find that at many retailers the sales never, or seldom, end. In a nine-month investigation, Checkbook found that many stores use deceptive practices, especially by offering continuous, misleading sales campaigns. The only way to know whether you are paying a fair price is to compare prices at several stores.

Use shopping bots and bar code scanners. There are dozens of smartphone apps that can help you compare prices, including ShopSavvy, Purchx, BuyVia and PriceGrabber. Amazon has integrated its price-checking tool right into its app. Use one of these apps to search for products or to scan the bar code of a product at a local store to get prices offered by other retailers.

Ask for a price match. Checkbook often finds the best deals online. But if a salesperson at a local store provided valuable buying advice, you might want to reward him or her with the sale. Or you may not want to wait for delivery by an online seller. And if it's an expensive item, you may have to be home to sign for it.

But at many stores, you can buy local and avoid paying more. Checkbook finds that retailers often will match lower prices offered by their competitors, even if the other seller is an online store. Just use your smartphone or take along a printout of your deal to ask for a match. While this tactic seems like a hassle, Checkbook's undercover shoppers found it was quite easy to secure lower prices on most items simply by asking for a lower-price match. One Checkbook shopper recently scored a $500 Kenneth Cole briefcase for $86 from a major department store by scanning the item with Amazon's app and showing the current Amazon selling price to a manager.

Know the code. When making purchases online, you will often see spaces where you can enter a promotional or coupon code. These spaces may as well be labeled "Hey! Here's free money!" Using a discount code is the equivalent of handing a printed coupon to a checkout clerk. Do an internet search for discount codes for the site (for example, search for "Lands' End discount code"). Although you will encounter expired codes, your reward often is worth the searching and trial-and-error.

Two of our favorite coupon sites are RetailMeNot.com and CouponCabin.com, but there are many others worth checking. We recently found discount codes that saved 25 percent off a contact lens order from Walgreens.com; cut 40 percent from a BananaRepublic.com order; lowered Orbitz's already discounted rate for a hotel stay by 15 percent; and zipped up a 30 percent discount on a pair of boots from shoes.com.

Get social. Follow retailers on Facebook, Twitter, and Instagram, and sign up for their e-mails, which many retailers use to announce exclusive discount codes and other deals. And many stores offer one-time discounts of 10 to 25 percent when you join their e-mail lists. Have more than one e-mail address? Sign up with another address the next time you are ready to buy.

Play your cards. You can usually get a big one-time discount for your first purchase made with a retailer-issued credit card, and with some you continue to get smaller regular discounts or rebates every time you use their cards.

For example, Target's Redcard offers a 5 percent discount on all purchases, free shipping on most items, early access to special events and promotions, and an extra 30 days for making returns. Credit cards offered by Gap companies (Gap, Banana Republic, Old Navy, Athleta) offer a 15 to 35 percent discount off your first purchase when you open a card account, then 5 percent rebates when you use its card at its stores. Customers who have the Visa versions of the company's cards also get a 1 percent rebate on all purchases made elsewhere.

Know that each application will trigger an inquiry on your credit report, and might negatively affect your credit score. Even more important: Most store credit cards charge very high interest rates (routinely 25 percent APR or higher); avoid these high interest rates by paying the bill in full each month.

Twin Cities Consumers' Checkbook magazine and Checkbook.org is a nonprofit organization with a mission to help consumers get the best service and lowest prices. We are supported by consumers and take no money from the service providers we evaluate. See all our ratings and advice free of charge until Dec. 5 at Checkbook.org/StarTribune/Save