1. Get a credit card if you don't have one Average amount of credit lines one should have should be between five to eight accounts. Don't fall for the myth that you have to carry a balance to have good scores. You don't, and you shouldn't. But having and using credit cards in rotation and paying them off can really build your scores. 2. Add an installment loan to the mix You'll get the fastest improvement in your scores if you show you're responsible with both major kinds o