Not everyone will agree with me on these ideas, but after the Holidays I do a lot of returns and take advantage of a lot of the sales.
After Christmas I try to return any unwanted gifts that my family received. I truly appreciate the thought behind the gift but find it wasteful to keep unwanted items. Many stores will not accept a return without a receipt or a gift receipt, but sometimes you can get a store credit. If I get a store credit, I either use it to buy something my family needs or I save it to purchase a gift for someone at a later time. If the items can't be returned, I usually save it to give to someone as a gift (re-gift) should it prove to be an acceptable item for such an occasion.
The other thing I do is to check to see if any of the items I purchased for Christmas have now been marked down on sale. If I find something that I already purchased on sale, I will buy the item at the sale price and later return it with the original higher receipt. This can save a significant amount of money.
This article has been included in the Carnival of Personal Finance #134 over at Mrs. Micah.