Retailers know the rush is coming, and they are doing everything they can to attract last-minute shoppers. [...] many retailers, such as Best Buy, allow shoppers to find an item online and pick it up at a store. Even 7-Eleven is targeting shoppers, offering gift cards, toys and stocking stuffers in its stores. Marshal Cohen, chief industry analyst at market researcher NPD Group, says many people do not yet know what they want to give, or get. The one saving grace is online (shopping) is a chance for a lot of people to do their homework. [...] prep work can save a lot of headaches and potentially limit last-minute impulse purchases that can prove costly.