Credit cards can be one of the easier ways to help build up your credit. If you use a credit card regularly and make regular on time payments, and never fully max out your credit card limit, this can be a great way to improve your credit score. The typical rule of thumb is to keep the balance on the card at a 10% utilization ratio. Example: If your credit card limit is $3,000, you should keep your balance at $300 or lower. Preferably you can be disciplined enough to pay it off each month after purchases.