NEW YORK (MainStreet) — If you ask consumers who use credit card rewards programs the most, they want cash back most, with frequent-flier miles a distant second.

Affluent credit card users are far more likely to tab "cash back," with 60% of Americans with investable assets of $100,000 or more opting for cash rewards, while 22% of the same group say they prefer frequent-flier miles, Austin, Texas-based CreditCards.comsays

If the wealthier among us value cash back that much, we all should. Credit card experts have suggestions on making sure we get it, starting with a warning:

"Cash-back is king, but job No. 1 for anyone with a cash-back card is to pay your balance off in full each month," says Matt Schulz, chief credit card analyst at CreditCards.com. "If you don't, interest charges can quickly surpass whatever you might earn in cash back."

You also need to pay close attention to deal terms to gain the most benefits.

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Here's a good example: You have to "opt in" on so-called "rotating categories" to really get the best benefits, Schulz says. "Many cash-back cards — such as the Chase Freedom or Discover It cards — offer up to 5% cash back on certain categories each quarter," he says. "However, if you don't opt in each quarter, you might miss out."

Randy Hopper, vice president of credit card operations at Navy Federal, the largest credit union in the U.S, says consumers may be looking at card rewards programs the wrong way, and thus missing out on benefits. "Consumers often spend far too much time focusing on the specific benefits included in offers and rewards, and they overlook the importance of straightforward, flexible rewards programs," Hopper says. "Research shows that many cardholders often miss out on a large amount of their rewards because of expiring points, or simply because they don't fully understand how to use them."

To look beyond specific card reward deals, Hopper advises making sure your rewards program is transparent and offers the flexibility you need. For instance, it's a good idea to avoid complex, multi-tiered point-accrual systems. "If you accrue points at a certain rate up to $5,000, and then your accrual rate is different at other amounts, it will be very difficult to predict and track your rewards benefits," he notes.

Also, don't let your card reward points expire. "Try to find a card with no points expiration, so that you don't risk losing out on your hard-earned points. And avoid waiting periods or other restrictions on your ability to accrue rewards," Hopper says. "You should be able to earn rewards from day one, with the first expenditure."

Common sense should also prevail. "People tend to pick a card that isn't a great fit for their lifestyle," Schulz says. " If you never fly anywhere, don't get an airline miles card, regardless of how great the sign-up bonus is - stick with cash back instead. If you don't want to devote much time to keeping with rewards, don't get a cash-back card with rotating categories. Just stick with a card that gives you a fixed percentage back on every purchase."

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To further accelerate your rewards leverage, broaden your search to include shopper loyalty programs. They are underrated, but effective. "Credit card sign-up bonuses are often the quickest and easiest path to travel rewards, but shopper loyalty programs are abundant and universally accessible," says Jason Steele, a credit card analyst at H&R Block. Common offers include shopping portals, restaurant rewards and bonuses for purchases from specific partners. "The idea here is to maximize your memberships by gaining points on purchases you would make regardless," Steele says.

You may have to pay more upfront to get a decent rewards card, but that's OK, because that's where the best deals are found, says Brian Kelly, founder of the popular card rewards blog ThePointsGuys.com.

"It makes sense to pay an annual fee on a credit card to get the most rewards," Kelly says. "No-fee cards generally come with the least rewards. So paying a little bit can get you a lot back in return."

Kelly adds that even with cards with big fees, such as American Express Platinum, you get $200 off a year right off the bat in airline rebates, plus lounge access to Centurion lounges, Delta lounges and other major airline member areas. "The savings go on, so you can easily recoup an annual fee many times," he says. "If you're not gaining more than the annual fee in value per year from your card, it's time to switch."

— By Brian O'Connell for MainStreet