Image: Woman with credit cards © Corbis

When it comes to cultivating a credit score, you've probably got the good-citizen routine down cold: You pay on time, try to wipe out the entire balance every month and never close too many accounts at once.

Beyond the basics, though, many consumers are still in the dark about what makes their credit scores go up and down.

"We have had so many people over the years who don't understand what goes into a credit score," says Dave Jones, the president of the Association of Independent Consumer Credit Counseling Agencies. "They just live with the old wives' tales."

Consumers understand that the credit utilization ratio -- the total amount of revolving credit someone uses in a month, compared with the amount of available credit the person has -- is a major factor in calculating a score.

But did you know that it's often calculated from the total on the statement date, not the due date? So even if you pay balances in full every month, a card issuer may report a balance. And that can hurt your credit scores.

Here are five ways you can use that bit of knowledge, along with some other expert know-how, to boost your credit ratings:

Pay bills before the statement date

Typically, the balance as of your last statement date is the balance that will be reported to the credit bureaus, says Barry Paperno, a consumer operations manager with myFICO.com, the consumer division of Fair Isaac, the company that created the FICO score. So if you pay most of the bill before the statement date, you can lower your utilization rate. And that can equal higher credit scores.

"How much you owe is 30% of your score, and the utilization ratio is a large part of that," says Paperno.

If you charge a balance every month but pay it off and can't understand why your scores aren't higher, it could be that your utilization ratio is what's depressing your scores, he says.

This might not work with every card. Some lenders don't use the balance on your statement date when they report to the credit bureaus. Instead, they select another day and report the card balance on that date instead.

Paperno's advice: Call your lender to ask when the balance gets reported.

Make multiple payments

Another way to lower the balance on your statement date is to make periodic payments throughout the month.

If you use a credit card throughout the week for everyday expenses and pay it off every Friday, you'll cut the amount of credit you're using at any one time. Check with your card issuer to learn how it handles multiple monthly payments.

"Basically, the lower the balance on your credit report, the better," Paperno says.

What you need to know: Your card company could place a limit on the number of times you can pay in a month, he says. All card companies will take two or three payments per month, but if you are paying weekly or more often, you should make sure the company is set up to handle such frequent payments.