Here's how to avoid spending too much on clothing, electronics and school supplies. By Cameron Huddleston, Former Online Editor Updated July 15, 2013 The start of the school year is still a month away for many students across the nation, but plenty of families likely are already doing their back-to-school shopping. And they're likely to shell out hundreds of dollars if last year's school-related spending is any indication of what to expect this year. Families with children in kindergarten through 12th grade spent nearly $690, on average, on school-related items in 2012, according to the National Retail Federation. That's a hefty price tag for back-to-school shopping. SEE ALSO: Outlet Malls: Deal or No Deal? Families can keep back-to-school costs under control, though, by developing a shopping strategy. Here's how: 1. Take inventory of what your kids have. Don't assume that your kids have outgrown all their clothes and need a new wardrobe. Take the time to make them try on what is in their closet and drawers to figure out which clothing items they really need. Then plan on buying items that can easily be mixed and matched. 2. Set a budget. Let your children know how much they can spend so they buy only what they need. You can motivate them to keep spending under control by telling them they can keep any cash they don't spend. Advertisement 3. Share the cost. Ask children who receive an allowance or who have money from a summer job to chip in -- especially if they want to buy more than your budget allows. If kids are expected to help pay for back-to-school items, they'll be more price-conscious. 4. Time your shopping right. Retailers offer some of the year's lowest prices on pens, pencils and notebooks in August. For clothing, you'll find deep discounts on summer apparel now (and you can layer light-weight clothing with sweaters, jackets or long-sleeve shirts to carry kids into fall) and look for sales on Labor Day weekend. Also, 17 states exempt back-to-school purchases from sales taxes on certain days. See my guide to sales-tax holidays . 5. Shop online. You may be more tempted to overspend when shopping in a mall, where you're surrounded by so many options, tempting displays and impulse buys in the checkout aisle. If you shop online, you can give your kids a choice of just a couple of retailers that have coupon codes -- which you can get from sites such as CouponCabin.com, Coupons.com and CleverTeens.com -- and free-shipping offers (see FreeShipping.org). 6. Use price-comparison sites and apps. To make sure you're getting the best deal on a computer, electronic gadget or school gear (such as a backpack), use a price-comparison site or smart-phone app for in-store shopping. Amazon.com, PriceGrabber.com and Google Product Search are great sites for price comparisons. And we recommend Amazon Price Check (Android, iPhone), Google Shopper (Android, iPad, iPhone) and RedLaser (Android, iPhone, Windows Phone) for scanning barcodes while you're in a store to compare prices with other retailers. 7. Buy discounted gift cards. Buying a discounted gift card to use for your own shopping is a good way to score additional discounts. For example, buy a $100 Gap gift card for $90 (instant $10 savings). CardCash and Gift Card Granny sell merchants' gift cards for less than face value. Advertisement 8. Check for student discounts. Some stores, such as Apple, offer discounts just for students. All it asks for is your name and school you are attending. 9. Sign up for e-mail or Twitter alerts from back-to-school retailers to know when their items go on sale. 10. Buy used. Textbooks are cheaper used (and even cheaper when you rent them). See How to Cut Your Textbook Costs in Half -- or More for Web sites that will help you get a deal on books. Also consider buying items such as computers refurbished rather than new. 11. Swap rather than buy. Outfitting your kids for school doesn't have to mean a trip to the store. Some kids will be content with clothing that is "new to them." For example, my younger daughter is usually pretty happy to get new clothes in the form of hand-me-downs from her big sister. So consider hosting a clothing swap with friends who have children similar in age and size to yours to freshen up your kids' wardrobes. Advertisement 12. Buy items in bulk to take advantage of larger discount coupons that give bigger savings for spending more. This is a good strategy to score savings on school supplies, such as paper, pens and pencils. Places such as Staples offer bulk discounts and free shipping. A final note: Don't buy something just because it's cheap. This especially applies to school gear that kids can use year after year. For example, if you purchase a quality backpack that costs more than a bargain model, you'll likely save money over the long run because you won't have to shell out money each year to buy a new one.