If you’re doing a lot of your holiday shopping online this year, it’s worth taking a moment to study the retailer’s return policy. Some stores, including Abercrombie & Fitch, DSW, H&M, J. Crew and Zara, have begun charging fees for purchases returned by mail. With the rising cost of shipping, as well as the labor it takes to inspect returns, retailers are discouraging people from ordering more items than they plan to keep. Their biggest headache is “bracket” ordering, where customers purchase multiple sizes of the same item and send back the ones that don’t fit. In many cases, you can avoid these fees by returning online orders to the retailer’s physical store. But some chains, including Uniqlo and Old Navy, have begun to impose strict rules about which online returns and exchanges can be handled in person.