Average spending on back-to-school has grown 42 percent in past 10 years, according to data from a National Retail Federation (NRF) annual consumer survey. Last year, parents cut back on their spending, from about $670 on average per family for K-12 spending to about $630 per family. Most expect to spend about the same this year.

Purchases include school supplies, clothing and electronics. The NRF survey also found that families are increasingly on the hook for helping to stock their children’s classrooms; parents said that 64 percent of their purchases of pencils, folders and other school supplies were influenced by classroom lists or school requirements.

If you’re hoping to save money on back-to-school shopping this month, here are a few ideas that may help.

Shop early and a little at a time: Many retailers rotate through deals every week – pens and paper one week, notebooks and pads another, backpacks the next. It takes a bit more time, but you can maximize your savings by purchasing only the sale items each week.

Use apps to save: Many large retailers (Target, Walmart, Sears, etc.) have money-saving apps with special coupons or discounts not available anywhere else. Often, the deals can also be used in conjunction with other sales and coupons.

Apps like Coupon Sherpa  feature online coupons, in-store coupons, and location-based coupons from many different stores. You can even select your favorite stores ahead of time, pull up a coupon while standing in the checkout line, and quickly collect your savings.

Mail in rebates: Rebates that give money back to shoppers who mail in paperwork after making purchases often offer the best deals. But you have to put the effort into completing the paperwork; set aside time to do so as soon as you return home from shopping, so you don’t forget and lose out on the savings.