My mom (who, incidentally, hates to shop) always told me not to buy something just because it’s on sale. I can’t say I’ve always lived by that mantra, but lately, it’s been ringing through my brain as I comb the racks of local discount stores.

Shopping has been a part of my life since I started earning a paycheck, and over time, I developed a set of rules to live by. The formula is simple and almost foolproof, with the exception of those Rollerblades I bought a few years ago, thinking I’d actually use them. And, if the rules are used wisely, they can help you save money, too. Here goes:

. If it doesn’t fit today, it won’t fit tomorrow. Don’t buy something that’s just a little bit off unless you can sew or have a tailor. Pant hems are the exception to this rule. Never buy anything thinking you’ll lose weight before some special occasion. Chances are the event will come and go, while your waistline-hips-thighs-butt remain unchanged.

. Don’t pay this season’s prices for last season’s styles, especially at an off-price store. Just because something has an Abercrombie & Fitch label on it doesn’t mean you should pay $30 for a sweater that went out of style last winter. This is my biggest pet peeve. You’re better off shopping the end-of-season clearance sales and getting 75 percent off the original price. For instance, I picked up a timeless olive sweater coat from Express’ fall 2001 collection at T.J. Maxx ‘n More recently for $14.99. That’s a bargain. Ditto for last winter’s Skechers boots, now at Marden’s for $19.99. Black boots never go out of style, and I paid more than $45 for the same pair last year before wearing them into the ground.

. Spend more money on clothing you’ll wear more often. Black pants, khakis, coats, plain sweaters, shorts and jeans are the staples of your wardrobe. If you pay $150 for a wool coat that you wear four months in a row, every winter, you end up paying less than 50 cents per use. If you buy a cheap, trendy top for $9.99 and wear it once before ruining it in the washing machine, well, you do the math.

. Designer on sale is like a straight flush. It beats a full house (of poorly made clothes, that is) any day. For example, you’ll get more wear out of a $30 Ralph Lauren turtleneck sweater on the clearance rack at T.J.’s than you will from a similar sweater from the junior section at the same price.

. When shopping at thrift shops, vintage stores or the Goodwill, keep three things in mind: quality, style and condition. Be sure to closely inspect sweaters for moth holes and shirts for spaghetti-sauce stains, makeup mishaps, or cigarette burns (prevalent on polyester). If you see anything high-end (Coach bag, Chanel sweater) at a ridiculously low-end price, buy it even if it doesn’t fit. Someone you know will love it.

. Never skimp on boots, winter coats or bras. Ever.

. End-of-season sales are the perfect time to invest in outerwear, garden supplies, big-ticket seasonal items such as lawnmowers, grills, or snow-blowers, holiday decorations, Christmas cards and any clothing with a classic cut.

. Rather than buy an ugly coffee table-lamp-comforter-bookcase because you can’t afford a nicer one, make do and save for what you want. Because once you have more money, you’ll end up buying what you wanted in the first place, after having wasted money on a stopgap purchase. Quality always beats a low price.

. Even thought it’s annoying, it pays to clip coupons, especially during a Filene’s One-Day Sale and at Shaw’s Supermarket.

. If you shop online or through a catalog, you’d better know what size you take. Otherwise, what money you may have saved will be wasted in return postage.

. Read circulars. Scan advertisements. Get a subscription to Lucky magazine. Unless you visit the stores every day, you have no way of knowing what’s on sale otherwise.

Of course, the most obvious way to save money is to stay home and not shop at all. But where’s the fun in that?

Reader question

Dear ShopGirl,

It would be great if you could locate a Playtex 18-Hour girdle brief for me. I was using Timeless Comfort from Sears, but they discontinued that line. I have a reunion this fall, and need firmer support. Maybe an out-of-town store still carries one or the other.

Thank you for your time.

– M. W.

Dear M.W.,

After a fruitless search in Bangor, I called an old standby, La Corseterie in Biddeford. The woman who answered told me that the 18-Hour girdle line has been discontinued as well. In its place, Playtex now sells the I Can’t Believe It’s a Girdle line, which is available in briefs and longer styles that look like bike shorts. The fit is comparable and the woman with whom I spoke said the fabric used is lighter, as supportive, and more flexible than that used in the 18-Hour collection.

Locally, you can find the “I Can’t Believe It’s a Girdle” line at Ames (but you’d better hurry, they’re going out of business) or you can order one from La Corseterie at (800) 400-6603.

Enjoy your reunion!

ShopGirl would love to hear from you. Send questions, comments or suggestions by mail to: Kristen Andresen, Bangor Daily News, P.O. Box 1329, Bangor, ME 04402-1329 or by e-mail to: kandresen@bangordailynews.net.