Around 70% of Americans have at least one credit card, but at least one in five of us has the wrong credit card, because the card doesn't align with our spending habits. 

In a best-case scenario, using the wrong credit card could mean missing out on valuable rewards. In a worst-case scenario, using the wrong card could mean paying hundreds in unnecessary fees or thousands in extra interest charges. 

You don't want to pay more than you need to or miss out on great rewards that could fund your trip to Tahiti or help pay for your retirement -- so follow these key tips to make sure you've chosen the right credit card to keep in your wallet. 

Pile of colorful credit cards.

Image source: Getty Images.

1. Compare credit card fees

Around 26% of credit cards charge an annual fee, and the average annual fee is close to $50, although some cards charge much more

Paying a fee sometimes makes sense, if the perks and rewards that go along with the fee are worth the cost. If the card has a generous reward structure and you can earn $500 more in rewards than you would with a no-fee card, it's worth paying a small amount to get that rewards boost. 

To determine if an annual fee is worth paying, estimate what you're likely to spend over the course of the year and how many points or rewards dollars that spending would earn you both on a high-fee card and a card without an annual cost. If you come out ahead with the card that charges a fee, go ahead and apply.

But be aware that if your spending patterns change or the fee goes up, that calculation may no longer come out the same -- and closing the card at that point could hurt your credit score.  If you have a card with an annual fee, it also doesn't hurt to call and ask your creditor to waive it -- 82% of respondents to a CreditCards.com survey successfully got their annual fee eliminated or reduced just by making a simple request. 

2. Determine if rewards are matched to your spending

Does your card reward you generously for travel -- even though you haven't taken a trip in the five years since you had your first baby? Do you get bonus points for restaurants but your gluten allergy makes it impossible to eat out? Your credit card isn't aligned to your spending and you may be missing out on earning the maximum rewards. 

When you compare credit card rewards offers, look where your biggest spending areas are and try to find cards that will regularly reward you for that spending. The Chase Sapphire Preferred Card, for example, is awesome for frequent travelers, while the Bank of America Cash Rewards Credit Card is nice if gas and groceries are your biggest expenditures. 

Alternatively, you could keep it simple and find a card that is relatively generous in rewarding all of your spending equally, rather than prioritizing one category over another. My recommendation -- a Visa Signature card that gives you 2% back on everything you buy, deposited right into a retirement savings account. 

3. Pay attention to the interest rate

If you're going to carry a balance on your credit card, a low interest rate should generally top everything else in terms of importance, because paying interest will cost you a lot more than the value of any rewards would. 

Average credit card interest rates range from around 13.24% for cash-back cards offering low rates to 20.9%. If you're late on payments, penalty APRs go much higher.

The rate you pay makes a big difference in total cost and debt payoff time. If you owe $2,000 and make $60-per-month minimum payments on a card at 13.24% interest, you'll pay off your debt in 42 months and pay $507 in interest. But if the interest rate jumps to 20.9% and everything else stays the same, you'll be paying your debt back for 51 months and will pay $1,019 in interest costs . 

There are plenty of great cards with a low APR, so there's no reason to pay more in interest than absolutely necessary -- although, of course, the best way to avoid interest is never to carry a balance at all. 

Choosing the card that's right for you

If you're not paying interest, deciding based on rewards usually makes the most sense. Whether this means getting a rewards card with an annual fee, or opting for a no-fee card with a generous cash-back plan, the key is to shop around and find a credit card that's the best fit for your particular lifestyle. This free guide to finding your perfect credit card can make the process easy, so find your perfect card today. 

Christy Bieber owns shares of Visa. The Motley Fool owns shares of and recommends Visa. The Motley Fool has a disclosure policy.