Summer doesn't begin until June 21 but with warmer weather and the kids out of school, Memorial Day has become the unofficial start to summer.

While many people travel during Memorial Day -- 39.3 million Americans plan to travel 50 miles or more this year (one million more than last year) according to AAA -- quite a few also use Memorial Day to get in some shopping.

Read More: These are the worst times to drive on Memorial Day weekend

Whether you choose to shop in stores or online you'll mostly see moderate discounts of 20 to 30 percent off depending on the product category. Everything ranging from apparel to home decor will be on sale, but shop selectively.

Purchasing summer items would be a mistake, according to the deal experts at DealNews. Focus on things like home decor, which last year accounted for 30 percent of all Memorial Day Sales.

Many pre-Memorial Day sales have already started and some sales will extend past Memorial Day, so be sure to give yourself time to compare deals.

Related: 10 ways to celebrate Memorial Day in metro Atlanta

Here are a few tips for making the most out of the sales:

Shop for Spring clothing: DealNews pros analysts said to expect discounts ranging from 20 to 90 percent off on spring apparel at specialty and department stores and 30 to 65 percent on designer items. Furla, the Italian handbag designer, is offering a 40 percent off private sale online. While Macy's is offering 25% off regular, sale and clearance purchase of $75 or more.

Stack your savings: Always look for ways to stack coupons and save more, not just on apparel, but also on home decor, travel, appliances and more.

Sleep on a new mattress: According to DealNews pros, May is a good time to get a new mattress. Groupon had mattress offers at up to 75 % off last year. US-Mattress and 1800Mattress had discounts in the 60-65% range. Expect to see prices for a twin-sized mattress starting around $125.

Take a trip: If you're not traveling on Memorial Day, it could be a good time to book travel for the summer. Last year, DealNews scouts saw solid sales for hotels and packages from Hotels.com and Travelocity, as well as direct flights from certain airlines.

Stay local: While some of the most advertised Memorial Day deals are from national retailers, don't forget that local retailers often run Memorial Day deals online and in-stores. This year for example, Dear Keaton, the Atlanta-based global lifestyle online destination is offering 20% off everything sitewide from May 27 - 29 with code MEMORIALDAY. And OkabashiUSA, makers of the American-made shoes focusing on foot health is offering 15% off sitewide on shoes for men and women. Use code OKABASHIUSA from May 27 - 29.

Here are some of current Memorial Day sales from national retailers listed by Deals Plus:

Amazon: Up To 70% Off Amazon Memorial Day Sale at Amazon.com

Bath & Body Works: 20% Off Including Memorial Day with Code: S175811 through 6/4 at BathAndBodyworks.com

Best Buy: Up to 35% Off Memorial Day

Costco: Online-Only Costco Home Savings Event & Memorial Day Deals through 5/28 at Costco.com

Dick's Sporting Goods: Up to 50% Off Memorial Day Sale + Free Shipping on $25+ at DicksSportingGoods.com (Spend $50, Get $10 with buy online and pick up in store)

Kmart: Save 10% Off $75 for the Memorial Day Sale + Free Shipping w/ Code: KMART10PSAVINGS at Kmart.com

Kohls: Cardholders with Code MOM30 & Code FREE4MAY through 5/21.

Lowe's: Shop Early Memorial Day Sale Savings with 25% Off Select Major Appliances $396 & Up at Lowes.com

Macy's: Pre-Memorial Day Sale + 25% Off $75 or More with Code CELEBRATE through 5/21

Sam's Club: Up to $1,300 Off Memorial Day Event on Appliances, Furniture, Mattresses & More through 5/29 at SamsClub.com

Sears: Up to 50% Off Memorial Day Sale on Appliances, Clothing, Home, Outdoor & More + Save $5 Off $50 with Code: SEARS5OFF50 or $35 Off $300 with Code: SEARS35OFF300 at Sears.com

Target: Up to 50% Off Pre-Memorial Day Deals & Coupons at Target.com

Walmart: Up to 50% Off Walmart Memorial Day 2017 Sale at Walmart.com

Yankee Candle: Memorial Day Sale with Buy 1, Get 2 Free Small Tumbler Candles with Code TUMBLER through 5/17 at YankeeCandle.com