The best shopping tip I have is Clearance Clearance. Clearance.
If you look for it you should find a clearance section in almost every store you shop at. Some have several. Food Clothing. Shoes. Stuff for your house. Etc.
Some of my best deals have been unexpected clearance finds and if you can combine them with coupons and/or rebates all the better. But it’s always worth an extra 5-10 minutes to check. You really never know what you’ll find unless you look.