The 2011 holiday shopping season is expected to extend at least another week, as four in ten Americans plan on hitting the stores over the next few days, according to a new Consumer Reports poll.

Of those who will be shopping the week after Christmas, 82 percent said the lure of post-holiday sales was the biggest reason, 47 percent want to redeem their newly-received gift cards, and 31 expect to be returning gifts.

Following are some of the tips from Consumer Reports for holiday shoppers:

Be Sure Before You Open That Box: Merchants can impose a restocking fee (often 15 percent of the product's cost), and many do for electronics items. Products such as computer software, CDs, and DVDs aren't generally returnable once they're opened. It might also be hard to return products with damaged packaging or missing tags.

Keep All Gift Receipts: These days, more merchants will turn you away if you don't have a receipt. If you didn't get a gift receipt with a product you want to return, you may be out of luck, unless you're prepared to ask the giver for the receipt.

Check Store Return Procedures Online and Note Time Limits: Big merchants usually allow 90 days for the return of most items but might have far shorter periods for electronics, software and CDs and DVDs. During the holidays, retailers sometimes extend deadlines.

Bring ID: Some companies require a government-issued ID with a receipt. That way, they can track serial returners even if the transaction is in cash.

Know Your Options: If an item was purchased online and the merchant has walk-in store locations, check the Web site to see if you can return it at a store and avoid repacking and a trip to the post office, as well as shipping fees.