Stores make advertisements on tv and the radio detailing their most sought after products and best deals. Catalogs or web pages with details about all of their listings and coupons to redeem are often utilized as well.
One big tactic in ads is that of showing the price of items before the sale and after the sale. To create a sense of scarcity, stores often implore shoppers to get certain items in limited supply before they run out and have different levels of sale at different times over the course of the holiday.