Gift cards have become an extremely popular gift. But to protect your money and get the most out of these plastic substitutes for cash, take these precautions.

Use your gift cards quickly. "The biggest mistake gift-card recipients make is to put their cards in a drawer and forget about them," says Trae Bodge, who runs the shopping-advice website True Trae. Almost $1 billion in gift-card value wasn't spent in 2015, according to the latest data from the market research firm CEB. Bodge says to keep your gift cards in your wallet or purse so that if you happen to be in the right store and see something you want, you'll have quick and easy access to them.

Protect your cards. The Federal Trade Commission warns that some issuers won't replace lost or stolen gift cards but others will, for a fee. Gift-card givers should give recipients the original purchase receipt in case the card is lost or stolen, the FTC advises. Some issuers require the receipt as proof of purchase to provide a replacement card with whatever remaining balance that wasn't stolen by the thief.

Recipients should also jot down the card number when they get it. If the issuer of your gift card has a replacement policy, make sure you register your card on its website. Promptly report a lost or stolen card, because you're unlikely to get back any value stolen before you reported the loss.

If possible, change the gift card's security code. A thief could drain the value of the card before you use it, though the incidence of this is low.

One way to protect yourself is by changing the security code on the card right after you buy or receive it. Not all card issuers allow you to do this, but some offer the option when you register your card online.

Spend all the money loaded onto the card. One frustration with a gift card is that after you use it to make a purchase, you may be left with a small balance, and it may not be easy to find something else to spend it on at the card issuer's store.

Liquidate small unspent balances by requesting a "split tender" payment the next time you shop at the merchant that issued the card, says Christina Tetreault, senior staff attorney at Consumers Union, the policy and mobilization division of Consumer Reports. That means you first pay with the gift card to use up the balance, then pay the rest using cash, a credit card, or a debit card. 

Some states give consumers another option. In California, for example, gift cards with less than $10 left on them are redeemable for cash; in Colorado you can get cash for gift cards with less than a $5 remaining balance. Find your state's gift-card laws at the website of the National Conference of State Legislatures.  

If you can't use your gift card, regift it to someone else. Maybe you received a gift card for a merchant or restaurant that's inconvenient or just not your favorite. Consider regifting the card to someone who would be better able to use it. That saves you from having to buy something else, and it could be a better option than trying to cash the card in at an exchange website where you may not receive the card's full value.