Taken from http://www.thesimpledollar.com.

When people discover a problem with their credit score, they often act rashly, doing things that seem as though they would improve your credit, but actually damage a credit score. Before we get into the ten mistakes to avoid, let’s first look at what makes up one’s credit score, as defined by Fair Isaac:

Although the exact formulas for calculating credit scores are closely guarded secrets, Fair Isaac has disclosed the following components and the approximate weighted contribution of each:

35%,- punctuality of payment in the past (only includes payments later than 30 days past due)
30% – the amount of debt, expressed as the ratio of current revolving debt (credit card balances, etc.) to total