Nobody's perfect. When it comes to our financial lives, we've all done things we later regretted -- whether it's getting slapped with a $3 fee for using an out-of-network ATM or going on a Las Vegas bender and losing the house on an overly aggressive poker bet.

Paying Late: Credit card companies are notoriously prickly about late payments -- even a payment that's late by a few minutes can pile up fees, interest charges and other penalties. Depending on how late the payment is, your card issuer may also report the problem to any of the credit bureaus, which can wreak havoc on your credit score. The good news, says Stacy Francis, president of Francis Financial, is that the error may be reversible. "You do have the option of giving the credit card company a call and asking them not to report it," she says. "If you've generally been an on-time payer, they may waive the fees and not report it."

Paying Only the Minimum on Your Card- Credit card companies love it when you pay off your debt slowly, but you should loathe it. It won't necessarily affect your credit score, but that doesn't mean it's a good practice. Sending in only the minimum payment "is definitely going to keep you in debt longer, and you're going to pay a heck of a lot more in interest," says Francis. "You may be paying twice as much -- or more -- as you would by paying in cash."

Buying On a Card Just For Rewards - If you're paying off your balance on time and in full, using your cards to grab extra rewards isn't necessarily a bad plan, says Gail Cunningham, spokeswoman for the National Foundation for Credit Counseling. "You can win the rewards card game if you know how to play," she says. "But you do have to know yourself." Because most people spend more when they're paying with plastic than with cash, be cautious and recognize when you're buying something only because plastic makes the purchase painless.

Missing a Payment - Not only are you going to be slammed with fees, interest charges and other penalties when you miss a payment, but you'll likely see a rise in your interest rates. If that weren't bad enough, you'll also have to contend with a significant hit to your credit report -- about 35 percent of your credit score is based on your ability to pay bills on time. As a result, you'll pay more when you try to get a loan. "Missing a payment has both immediate and long-term consequences," says Clarky Davis, Care One Debt Relief's Debt Diva. "You may be dealing with the fallout for years."

Having Too Many Cards - If you're the type to apply for a card just so you can grab a discount on clothes or other merchandise, you likely have a huge stack of cards in your purse or wallet. You're probably not getting enough value from the card to make it worth the high interest rates or additional complications from additional bills and junk cluttering your mailbox -- and you're increasing the likelihood that a payment slips through the cracks or that you'll be a victim of identity theft. "There's rarely a good reason to get a new card if you've already got a general-purpose card, a rewards card and a low interest card," says Cunningham.

Maxing Out a Card - Maxing out a card can have a serious impact on your credit score, since about 30 percent of your score is based on "credit utilization" -- the amount of credit you've used relative to the amount you have available. More important, says Davis, is the fact that it likely signifies a distressing trend in your personal finances. "Maxing out a card may not have an immediate financial pull, but it's a sign that you're not budgeting or spending your money wisely," she says. "It means you don't have enough saved up to cover unexpected expenses."

Playing the Balance Transfer Game - Moving your debt from a high-interest card to a low-interest card with a balance transfer isn't as smart a move as you think, says Francis. "About 15 percent of your credit score is affected by your recent credit applications," she notes. Pile up a few transfers and your score will take a hit. "Credit bureaus don't (differentiate) that these cards are for the same [debt], they just see it as you getting pre-approved for more and more credit." Add in the fees that generally accompany balance transfers and you're not gaming the system -- you're getting hammered by it.

Debt Settlement Plans - If you're overwhelmed by debt, negotiating down your balance with the credit card company (also called debt settlement) sometimes helps you pay pennies on the dollar on your debt -- but you'll pay a steep price. First, there's the tax hit you'll take for the amount of debt that's forgiven -- it will count as income during that tax year. And your credit score will be decimated, so don't expect you'll be able to take out a loan soon after consolidation. Next to bankruptcy, debt settlement "is the most negative thing you can do to your credit score," says Francis.

Getting a Cash Advance? - It may feel like free money, but the truth is that it's anything but: You'll likely have a fee associated with the advance, and you'll likely pay a higher interest rate than you would by using the card associated with it. "You also have no grace period," notes Cunningham. "You'll start accruing interest from the moment you get the money." While these are all dangerous attributes in and of themselves, they're not the worst part, says Cunningham. "When you start using cash advances, you have to understand why you're using them as they're likely symptomatic of a deep financial problem."

Using a Card in a Pinch- If the fridge went on the fritz or the furnace conked out in mid-January, you might not have the means to fund its immediate replacement. Putting the bill on a credit card -- and paying it off quickly over the course of a few months -- is a pretty solid option, says Cunningham. "You don't want something like that to become standard operating procedure," says Cunningham. "But it's OK to have a balance on a card for a few months when you're going through a rough patch in your financial life. Just make sure it's on a card without an annual fee or with a very low annual fee."