Shopping lists are so easy to write. Sticking to them? Not so much.

Mind Over Money author Eric Tyson has formally researched this truism, and even explains how to overcome our faulty psychological wiring so we can do things like, well, stick to our shopping lists. At least I think he does.

When I went to the bookstore to pick up a copy of his book, I got distracted by the latest issue of Elle Decor, a new day planner, three birthday cards, and a friend of mine in line at the checkout counter. (Remind me to jot down the title in the "To Do" section of my cute new pocket calendar.)

How to keep yourself honest at the checkout counter
Here's your first tip to trimming your overall spending tab -- a shortcut, even: Stop reading right now and print this page. Now put it in your wallet, purse, pocket, shoe, or wherever you're most likely to notice it before you reach the cash register. Vow to try to follow at least one of these rules (or even three, if you're in the mood for extra credit) the next time you're in a particularly acquisitive mood.

Ditch the plastic and pay with paper money. The advice may be obvious, but curbing credit card use is one of the best ways to squelch a spending problem. Keep the cards at home and carry cash, checks, or a debit card. An obstacle? Yes. But so is a mountain of credit card debt.

Record every retail atrocity. In that cute little day planner, write down everything you purchase over the course of a week (or two days or however long you can stand it before you gag). Just the act of noting the "non-essential purchases" will likely curb your enthusiasm at the checkout counter. If after a week you find yourself going back to old habits, reinstate the exercise. (Your shortcut here is to use free -- and scarily simply -- financial tracking software, like Mint.com. See "Stop Mistreating Your Money" for more.)

Drag your best "frenemy" to the mall. The best spending deterrent in the world is a frugal friend who isn't afraid to nag (good friend, shopping enemy). Or roll his or her eyes. Or hold onto your wallet. When they're not available to play bad cop, see your inner money shrink. In other words ...

Do some shopping self-help exercises. When you grab that [insert your last impulse purchase here], even if it looks fabulous when you try it on, don't put it in your cart until you ask yourself this one important question: Do I need it? C'mon. Do you really? That's what I thought. Author Pamela Danziger (who wrote Why People Buy Things They Don't Need) says that we shop to gratify a desire, and the actual act of consuming (strolling the aisles, trying things on), rather than the item consumed (actually buying the aforementioned impulse item), satisfies our emotional needs. She's right. Often when I walk out of the store empty-handed, I feel perfectly sated and proud about the money I "saved" by not spending it. Which leads us to ... Continued...