FICO Breakdown: How Your Credit Score Is Calculated

35% - Payment History. Meaning any lates; collections; charge offs; bankruptcies; judgments; liens or the such will hurt the score. All is time based, the older the information the less it is contributing to the scores.

30% - Utilization. It is best to have several accounts with low balances distributed then it is to have fewer accounts maxed out. To figure utilization: Balance (divided) by Credit Limit = percentage. Lower than 10% recommended per account, this is one of the fastest means for increasing the over all credit score.

15% - Established History. The longer you maintain open accounts with creditors the better. When first starting out of course this is not easy; but this is where getting added as an Authorized User to another persons established credit comes in best. Remember that the contributor must have an account that has long history; clean payment record; high credit limit; and low balance. Also need to check with the creditor to insure that they have a policy to report authorized user accounts to all three major credit reporting agencies.

10% - Inquiries. Don't apply for credit unless you know you can get it or that you need to get it; unnecessary credit inquiries are going to hurt the scores - especially if your over all credit file is small to begin with.

Tip: When applying for credit pull your own credit report first (this is a soft hit and won't drop your scores). With credit report in hand go visit your local banks or credit unions. Show them the reports; and don't allow them to pull a credit report of their own unless they can say for sure that you will be approved, this way you save your self unnecessary pulls on your credit report if they decline you. If they say yes, you are approved, then they will need to pull credit report to seal the deal.

10% affects Mix of Credit. Use different types of credit (revolving; installment; auto; mortgage...) evenly.

How to I dispute inaccurate info?

Experian: 

Transunion: 

Equifax: 

Sources:

FTC: - Building a Better Credit Report

FICO Score