A common -- but not always easy -- way is to pay your bills before their due date.

It can happen in a flash. For example, if you don't pay a hefty overdue fine on a library book, a collection agency can end up dunning you for the outstanding fee and, boom, you've lost credit.

Among many other places that this is discussed, debt-free living is discussed on radio shows and Web sites. Chances are, though, it's not done at PTA meetings or with your bank manager!

According to some studies, the figures may not necessarily be an accurate measure of credit worthiness.

It could knock off 100 points out of a maximum of 850.

Here's the weird rule. If you cancel a credit card in order to reduce your spending, you may be damaging your credit rating. Go figure!

They go according to the ratio between your credit (which may have a high limit) and your debit (how much you owe).

Fair Isaac Corporation developed all kinds of algorithmic credit models. Hence, a FICO score.

Old debts seem to be less problematic than new ones. And trying to rectify old ones can actually harm your credit worthiness.

It appears as recent or new activity. Thus, what was an "old" debt becomes new baggage and damages your credit score.

Late payments are the ultimate no-no. That's probably the worst you can do to harm your credit score.

They call it a charge-off; an ambiguous term, which might also mean that they charge off to the local collection agency and report you.

It can be reported only for seven years. That might be good news for some, depending on who you are.

You still have to pay back every cent, but you don't have a credit limit.

It's called a domino effect. It starts with a mere late payment, which causes a hounding from a collection agency, then poor credit history and so on.