One mistake people sometimes make is closing off their credit cards so that they have no open accounts.
With no open credit card accounts and all your auto loans, student loans, and other installment debt paid, your credit score will disappear. This is because the credit bureaus have no way of rating your credit when you have no credit!
I believe in living debt-free. However, it is imperative that a person keep two to three credit cards open and active in order to qualify for the best mortgage at the best price. Otherwise, you could find yourself being forced to take a higher priced mortgage — or pay all cash for your house.
For a conventional loan, lenders want to see three trade line accounts. A closed installment loan (auto, etc.) is acceptable if it is not more than three years old.
For an FHA loan, lenders want to see two trade line accounts.
You do not need to carry a balance from month to month. In fact, it is better for your credit score if you pay off the balance in full each month and avoid paying interest. You can use the credit card minimally once a quarter to keep it active and accruing credit score points.
I urge you to pass on this information to folks who have dug themselves out of debt and then make the error of closing down all their credit cards. People get so sick of being in debt, that when they are finally free of that burden, they shut down all their accounts. THIS IS A BIG MISTAKE! Unless you are financially independent and will be paying cash for your houses, you need some open credit and a credit score to get a good mortgage.