I've earned $3,000 in rewards in the last decade by using an easy strategy whenever I buy gifts online

• I never feel guilty spending gift cards on things I want, which makes them a versatile gift.
• Using shopping portals, I can get even more out of purchases, including airline miles and more.
• I can even "double-dip" on rewards by using a credit card that offers cash back.

Gift giving is one of my top love languages. I love buying presents for people who touch my heart, even if I've only met them once or twice. If I've ever asked you for your address, you've probably discovered a card and a care package in your mailbox a week or two later.

I also fall in the camp of people who adore and appreciate gift cards, especially for retailers I love. To me, gift cards represent guilt-free spending money — they allow me to treat myself a little bit without feeling like I should be investing the funds instead. I also love that I get to choose what I really want to buy, instead of sticking with something someone chose for me or awkwardly sneaking back to the store to exchange my gift.

Even though I don't really drink coffee, for instance, I always find Starbucks gift cards useful. I can gift them to flight attendants when I travel, drop them in a gift bag to complete a white elephant gift, or add them to my Starbucks account for the rare occasions when I do order something.

I try to earn rewards whenever I give gifts

One of my favorite ways to earn rewards on my gifting habit is by using shopping portals for cash back and travel rewards. A shopping portal is a website that rewards you for clicking through its affiliate link to shop with online retailers such as Sephora, Nordstrom, Nike, and Lululemon. You can earn points, miles, or cash back on products, online services, floral deliveries, plumbing supplies, and so much more.

You probably know of a few shopping portals, even if you don't think you do: Rakuten Rewards, which used to be called Ebates, is a popular one. So is TopCashBack. There are hundreds of shopping portals out there, each offering different earning rates for the various retailers in its network. Some airlines and hotels even offer their own shopping portals.

Maximizing my rewards with online tools

To make sure I'm finding the best rate of return on my shopping portals, I use a web tool called Cashback Monitor to help me find the highest deals being offered at the time. I search for the name of the retailer I'm planning to shop with and click through to that page to see which portal offers the best reward — or the one that makes the most sense for me at the time.

If I'm trying to save up enough United MileagePlus miles to fly to Europe, for example, I might choose a lower rate of 3 miles per dollar instead of opting for 5% cash back per dollar. But if there's a cashback offer for 12% back per dollar, it might well make sense for me to choose that option over airline miles.

Since I first discovered shopping portals in 2013, I've earned more than $3,000 in cash back rewards in addition to enough airline miles and hotel points for a round-trip flight and two-week stay in Australia and Bali.

In fact, I just recently cashed out some of my TopCashBack earnings into a $600 Hotels.com gift card at a 5% bonus rate, which means I received $1.05 Hotels.com credit per dollar that I had earned through TopCashBack. That gift card will make a really nice wedding gift for some loved ones to use toward their honeymoon, and it didn't cost me a dime more than I had already spent on other purchases.

Doubling up on my gift-giving rewards

Even more excitingly, I've been able to "double-dip" my rewards by paying for my purchases with credit cards that earn bonus points for every dollar I spend. For example, my credit card earns 1.5% cash back on every dollar I spend. If I'm buying flowers, I might see that Rakuten has an offer of 15% cash back per dollar. That means I earn $16.50 in cash rewards for a $100 floral arrangement — on top of the undying adoration of my friend who receives the bouquet, of course.

So next time you're buying someone a gift, skip the mall crowds. Stay in your cozy pajamas and sip a hot beverage while you shop from the comfort of your computer. And instead of burning gas money, earn some rewards instead by using a shopping portal. Just remember to plan ahead for shipping times if you need your gifts to arrive by a certain date. And read the fine print: Some shopping portals won't give you cash back if you use a coupon code that isn't listed on their website.