Call your credit card company and ask to have your limit raised. High credit lines help to improve debt ratios, positively impacting score. A balance of $3,000 on an account that has a limit of $4,000 results in a debt ratio of 75%. A debt ratio of 75% makes a borrower looked "maxed out," negatively impacting score. In this case, if the total line could be raised to $6,000, the debt ratio would be reduced to 50%, positively affecting the consumer's score.

Negative items posted to a spotless record have a greater impact on than negative items posted to a profile that already contains a history of late payments. If your credit is "perfect" and you get 30 days behind on your car loan, the effect could be dramatic-25 to 60 points, for example.

The scoring model lumps auto and home loan inquiries made within a 14-day timeframe together. Car dealerships, for example, need to pull credit in order to see what financing a borrower is qualified to receive. The same goes for home loans. If you are in the market for a home or auto loan, do all of your shopping within a 14-day period so that the multiple inquiries will be counted as a single inquiry.

The scoring model looks less favorably on store charge cards than it does on VISA, MasterCard, American Express and Discover. "Would you like to save 10% by opening a Target card?" These offers sound tempting, but taking advantage of such offers can have a negative impact on your FICO rating. However, closing existing gas or department store accounts could hurt your score if those accounts have established histories.

Closing unused accounts deletes established credit history. If you have a card with five or more years of established history, hang on to it. The scoring model looks favorably on well-established histories. If you have balances, closing unused accounts also raises your debt ratios, negatively affecting your score. Remember that you can always cut up the plastic, but keep the account open to preserve account history.

The scoring system frowns on finance companies. Pay off finance company debts and never again use finance companies.

The scoring model takes into account how long it has been since a certain account was used. Utilized credit lines (assuming they are paid in a timely manner) positively affect credit score. Cards that collect dust in your dresser drawer do not help your FICO rating.

If your FICO file is "thin," work to establish three or more significant credit relationships-a home loan, a car loan, and a VISA card, for example.

The FICO model gives more serious consideration to recent items. Your previous 24 months of history is crucial. If you have had a bankruptcy, charge off or foreclosure that is more than two years old, you should still qualify for a home loan if your past 24 months of history is spotless.

Realize that 25% of credit reports contain errors sufficient to deny consumers access to credit.