If you do forget and are a good customer, Harzog says, contact the issuer and see if it will allow you to still qualify for the higher rebate.

Annual fees Cash-back cards usually don't charge an annual fee. But others that do, especially airline reward cards, are now waiving the annual fee for the first year.

If you are considering a card with a fee, do the math to determine if the benefits are worth the fee.

The Blue Sky Preferred from American Express assesses a $75 fee. But it also gives a $100 airline allowance that you can use to cover baggage and flight-change fees or meals on the plane, Harzog says. "Right there, you are still ahead $25," she says.

But the American Express Platinum charges a whopping $450 annual fee. Though the card has exceptional perks, such as a $200 annual airline allowance, you must be a heavy traveler who values these benefits to make the stiff fee worthwhile, Harzog says.

(Amazingly, the $450 fee isn't the highest. The fee for an American Express Centurion card, available by invitation only, is $2,500 a year. Imagine the rewards! You have to, because American Express doesn't disclose them to the uninvited.)

Cash vs. miles vs. points "With reward cards, it's not necessarily one-size-fits-all," Arnold says. "It depends on your spending habits and personal preferences."

Arnold says he favors cash programs because they're straightforward, and the average person tends to reap a bigger benefit with them.

There are exceptions, he adds, such as airline reward cards that waive fees and allow you to quickly earn a couple of round trips.

But points that can be used to purchase items can be complicated, Arnold says, and the merchandise is usually marked up. You would be better off many times earning a cash reward and using the money to buy the item for less at a store, he says.

Don't carry a balance If you don't pay off your credit cards in full each month, you need a card with the lowest possible interest rate — not a reward card.

Reward cards typically charge a higher rate of about 1 percentage point over cards without such perks, Arnold says. By rolling over a balance month to month, the interest you'll pay will wipe out any reward you earn.

Don't be late Some issuers won't pay rewards for the month if your payment is tardy. Or you can lose some or all of your rewards if you fall into arrears, Harzog says.

If you're struggling to pay a bill, says LowCards' Hardekopf, at least make the minimum payment on time so you don't lose rewards.

Maximize rewards If you shop online, check out whether the card company has partnerships with retailers. By accessing these retailers' through your card company's website, you might get a discount on merchandise, free shipping or extra cash back.


Best credit cards

Cash back