If your wallet is full of plastic and your mail is full of bills, it might be time to organize your credit cards. In fact, if you are carrying quite a bit of debt, consolidating to a lower-rate card can save you a hefty chunk of change in interest charges. But done incorrectly, canceling credit cards or consolidating debt can cause more harm than good.

Do you need to consolidate?

"If you really want a get-out-of-debt-free card, you've got to understand how you got into the mess and fix the mess," says Wayne Bogosian, co-author of " The Complete Idiot's Guide to 401(k) Plans."

"People solving symptoms with debt consolidation are on the verge of making the problem worse," he says.

In short, don't consolidate your credit cards just to charge them all back up again.

Which cards to keep?

Do you have multiple department store or gas cards that you never use? Are you paying a yearly fee for a credit card that allows you to earn miles? If so, do you plan to use those miles? Consider how many points you earn and if it's worth the fee you pay.

Follow these steps

• Pay off any low-balance cards you will not be keeping, and then close the accounts.
• Transfer the remaining balances to the card with the best interest rate. Don't use this card until it's paid off. This will avoid additional interest charges on revolving purchases. Once the balance is paid, close the account.
• Choose the two or three cards you are going to keep, and be sure they have limits high enough to cover your monthly charges. Close the others, and be sure to pay these off in full each month.

How to transfer a balance