This topic does seem a little self explanatory, but sometimes it is easy to get caught up in purchasing something, just because you have a coupon on it or it's on sale. Make sure that what you buy is something you need or will use. I do have a few exceptions for this rule. The first exception to the rule is that if it is Free, you can buy it, so to speak!
Another exception is that if it is a product that you would like to try out, go ahead if you can get a really good deal on it. Now, I get a little crazy sometimes with toothpaste - it's always either free or under $.50 a tube, so I keep getting it. My husband was getting so mad at me for buying. This leads to my next exception to the rule:
If you can donate it and it's either FREE or cheap, go ahead. We have a food pantry basket at church, which we give to needy families in our church as the need arises. This is where my excess toothpaste has been going little by little. That way, I can give something that is new and perfectly good and it may be useful to those in need. I know when money is short for us, the last thing you really want to purchase are the necessities!
I think the main point of this rule is to be sure not to be stocking your shelves with so much overstock that you can't possibly use it up in the next six months. Also, if your food shelves are getting too heavy laden, challenge yourselves to have a shopping free week and use what's on your shelves for menus. Also, you could put together a basket of necessities for a family in need or your pastor's family. They often appreciate the thought! I know a lady who gives all her siblings and their families a basket of soap, toothbrushes, toothpastes, body washes, etc. for Christmas and they all love it because they don't have to get those things for awhile! Be Creative! Let me know of any other ideas you might have!