You may have heard that it’s a good idea to “shop at home first” regarding groceries. This means that you go through your cupboards and cook using ingredients you already have instead of going shopping. But this idea can be modified to fit other situations as well.
For example, my husband had been wanting some new CDs, and so he made up a list of what he wanted to get. Instead of running to the store to get them, he went through the CDs we already had first to be sure he wasn’t duplicating anything. He found that we already had 3 of the CDs he wanted, so he saved at least $30 by checking to see what we already had first.
I think this kind of thing is pretty typical. I might think that I need a new white blouse, but if I go out and buy it, chances are that when I get home & hang it up I’ll find a white blouse I’d forgotten about at the back of my closet. Much better to take a few minutes to check first. It saves time, money, and gas.