1. Shop at a clearance outlet
Not to be confused with a factory outlet, clearance outlets, such as those for Sears, are where stores sell items that are out of season or didn't sell during sales. Just make sure the items aren't damaged. Typically, you can save up to 75% (or more) off the original price.
2. Buy on eBay
If you're going to buy here, go for lots. Buying lots allows you to save on shipping. This isn't the place for the finicky to purchase - you can't try on items before you buy and returning an item is a dog's breakfast. However, you can get amazing value.
3. Dollar Stores
No, this isn't a joke. Sometimes, dollar stores (not usually the true dollar stores, but rather the buck or two type) will taken on inventory that didn't even sell in the clearance stores. Gems aren't abundant here, but they can be found.