If you've had the same card for years, you could well be paying far too much for it. If you have a good credit history, your card should cost you less than 12% APR. If it doesn't, transfer your balance to one that's much lower. You could get one that not only suspends charging you interest for a given amount of time but also only reverts to around 8% APR when your interest free period is over. Check out some comparison sites such as moneyexpert.com to find some of the best deals available.

However, if you do this, be wary of what the interest rate goes up to once your introductory rate expires. If it's a much higher rate than the one you're paying now, ultimately the balance transfer will have cost a lot more.

If you have several cards or even just one with a large outstanding balance, consider getting a home equity loan to pay them off. Instead of paying double figure interest on your card balances, a home equity loan is likely to be around 7% APR so on a large amount you could save hundreds of dollars a year.

Also watch out for the hidden fees that you could be getting charged on your cards. For instance, if you were to go over your agreed spending limit, you could be charged up to $40 and beyond for each month that your balance remains above your limit. You should also be wary of the conditions that apply to any grace periods you're offered with new cards because they often don't point out to you that the interest free offer only applies if you settle your balance in full at the end of the grace period.

If you discover that the interest rate has gone up on your card, call your card issuer and tell them that you intend to transfer your balance to another credit card issuer who has a much better rate. It's surprising what lengths they'll go to and how low they'll make your rate if they want to keep you!

Finally, many people use their credit cards with certain retailers because their card issuer promises a cash-back reward for every purchase. That's fine, but let's say you buy a toaster from retailer A, who is partnered with your card issuer; it costs $20 and you'll get $2 back for buying there. Next door, in store B, the same toaster is $15 but you didn't shop there because it's not a cash-back partner- you still paid $3 too much!

It's important to keep these things in mind when using credit cards. Don't believe the hype.