Low utilization, different types of credit accounts open, and a long enough credit history should do the trick. (biggerpockets.com)
Credit age refers to the length of time you've had credit accounts, both the age of your oldest account and the age of all your credit accounts averaged together. (creditrepairreview.com)
A credit card is a revolving line of credit account which requires monthly payments, balance management and approval for transactions. (stockmonkeys.com)