Fight back

Technology can be a valuable tool for managing your credit cards. Money-management sites such as Mint.com and Quicken Online are free and can help you track expenses among checking, savings, and credit-card accounts. The most efficient, safest, and fastest way to pay a credit-card bill is to let your bank do it automatically or set up automatic payment through the card issuer's Web site.

Rebecca Schreiber, a financial planner in Silver Spring, Md., recommends using a debit card for day-to-day purchases, such as going out to dinner or buying a new outfit, while using your credit card only to pay fixed monthly expenses, such as cable, car insurance, and cell phone bills. Then have your bank automatically pay your credit card every month. "This way," Schreiber says, "you'll build up your credit score with regular charges and payments, pay off your balance every month, and avoid putting impulse buying on a credit card that will haunt you for years."

If you are carrying a balance and use online banking, try chipping away at as much of the balance as you can each payday—weekly or biweekly—rather than letting money sit in your account while you wait for the monthly bill. That can save you significant interest.