Most times finding the best deals involved knowing where to look. Sites such as retailmenot.com and promocodes.com can share promotional discounts on stuff you may already be buying on sites you use every day. Joinhoney.com will install an extension on your browser to do this automatically.
In addition for some big sales, if you can wait, there are certain times of year that some items are priced aggressively. If you can time your purchase you can save.
January: Linens, bedding, exercise equipment, winter clothing
February: TVs, tax filing, cookware, small kitchen appliances
March: Skis, snowboards, high end fashion, luggage
April: Tires, cruises, and hotel discounts
May: Mattresses, smart home hubs, furniture
June: Gardening tools, gym memberships, camping gear
July: Swimwear, air conditioners
August: Laptops, school supplies, shoes
September: Older phone models, grills, summer clothing
October: Last years cars, Halloween costumes, patio furniture
November: Gaming systems, tablets, large appliances
December: Jewelry, toys, wedding dresses