Steve and Lisa's Mortgage Morsels

Each comprise 10 percent of the total credit score. Borrowers, even those new to credit, should avoid opening too many credit lines at the same time, since such behavior could suggest they are in financial trouble and need significant access to lots of credit. FICO suggests that borrowers only take on additional credit when they must have it or when it makes sense financially.

Credit mix: This is somewhat of a vague category, but experts say that repaying a variety of debt indicates the borrower can handle all sorts of credit. According to FICO, historical data indicates that borrowers with a good mix of revolving credit and installment loans generally represent less risk for lenders. Knowing the various weights given to components of a FICO credit score give borrowers a better idea where to focus their attention.

"So to get a good score you mostly need a credit history with no reported late payments, as well as low reported balances currently on any credit cards," Watts says.