Many Americans have a healthy fear of credit cards. Used wisely, however, they can be a powerful financial tool, adding convenience, tracking and rewards to your life.

There are three keys to turning a card (or cards) to your advantage. The first is knowing your own spending habits. The second is knowing APR, or annual percentage rates, on cards; and the third is finding a card with the lucrative rewards – the kind you use.

To pick the card that’s right for you, ask yourself three questions:

1. Do you have debt, especially high-interest debt? This question is more important than any other. If you have debt for which a credit card company is charging you a high rate of interest, the most important thing you can do is pay it off.  The average household has more than $8,000 on their cards, according to WalletHub, and companies can charge upwards of 20 percent in annual interest. If you have high-interest rate debt, look for a card with 0 percent interest on a $0 balance transfer fee. Transfer your debt to it.

If you can’t find an offer, or your credit isn’t good, call the credit card company. Ask if the company will lower your interest rate for you, or if you can negotiate a settlement. You can also reach out to a debt settlement company for help.

2. Do you need to build or restore your credit score? If you are having trouble getting a new card, you might be able to qualify for a student credit card or a secured card, which requires a small deposit – usually a few hundred dollars. Keep in mind that you build a good credit score with good spending habits: Paying bills on time, in full, and using your card within your means. Credit bureaus consider your average balance in relation to your income.

Help yourself by looking at your statements to see what you’re spending on. Identify the emotional triggers that cause you to overspend. Set up automatic payments from your bank account, so you’ll never be late. If you’re not sure you’ll always have enough to pay in full, set an automatic payment for the minimum due, which will also remind you to pay the bill in total.

To keep your spending manageable and keep your credit card usage down, consider paying your bill every two weeks. You’ll keep closer tabs on your spending that way.

3. What kinds of rewards do you want? It is possible to save thousands of dollars a year with the right rewards card. There are two general types: cash back, with some of the best offers ranging up to 5 percent cash back, and travel cards, with the best offers usually offering 1-2 miles for every dollar spent. You can find cards that offer rewards on different airlines, or cards that offer – typically higher – rewards limited to one airline. The site NerdWallet has several lists of top credit card offers. Take a look if you want to maximize your rewards. But remember, the rewards come after you learn to manage your spending wisely.

Credit cards can make your life more convenient and save you money – but don’t pay too high a price for either of those features by letting your spending and the interest you pay get out of control.

A CFP® professional can help you with a holistic plan that makes use of the best financial tools.