From a $1.49 bag of Lays of potato chips, I found a valuable lesson in personal finance and dieting. And that junk-food tutorial will dramatically change the way I shop and spend money. Here's what happened. When I cleared chips from the dining room table, I absentmindedly stuck my hand into the bag and crammed a handful of chips into my mouth.

But I wasn't hungry. But I was eating. But I wasn't thinking. But I was eating. Finally, my brain kicked out of the standby mode and I suddenly understood the 10 commandments of dieting, including the prohibition about eating while standing. In the upright position, it's incredibly easy to mindlessly consume calories.

That's why dieting gurus always warn about eating while standing up. It's so easy to stuff my mouth with food without thinking. But when I sit at the dinner table or the breakfast counter, I'm more mindful of the process and I consume less.

That realization made me think about spending: In the grocery store, in the mall and in the clothing store, I'm usually standing when I make a purchase. But I now believe that if I sat down and thought about the merchandise in my cart, maybe I would spend less. Many stores--even grocery stores--have areas where I can sit, chill and rest.

The health food store has a juice bar/cafe area; my neighborhood Target has a Starbucks corner and the grocery store near my home has park benches in front and even a little eatery inside. Buying a small cup of coffee could save me a fortune if while sitting, I carefully edit my shopping cart.

Think about it: When we make big purchases or large financial commitments -- a car, a home, college tuition -- at some point in that process, we actually have to sit down to sign papers or to test drive the car or to review documents.

From that seated position, we have additional opportunities to consider our options and make thoughtful choices. During those moments, we negotiate with the sellers and with ourselves: Do I really want this merchandise? Do I really need it?

But in the mall and in most stores, we're often upright and on automatic pilot. And from that position, we leave a large trail of small coins and crumbs. We leak money without really thinking. So I'm not going to a) eat while standing and b) make a purchase without sitting down to think.

Of course, I will still eat potato chips, just smaller portions at the table.

Editor's note: Sharon Harvey Rosenberg (The Frugal Duchess) will be joining Wise Bread as a full time blogger in August. In the mean time, she'll be dropping by with a few guest posts a week.  You can find more great tips from Sharon in her book Frugal Duchess: How to Live Well and Save Money or in Wise Bread's new book 10,001 Ways to Live Large on a Small Budget.

Can't wait until August? Here are other great posts by Sharon on her blog The Frugal Duchess. Enjoy!