If you are hoping to have a good enough credit score to be approved for a SunTrust card or any other credit card, there are a few rules of thumb you’ll want to follow. First of all, make all your credit card payments on time. That means paying at least the minimum due by the payment due date. In fact, paying all your bills on time, including mortgage payments, utility bills and student loans will also go a long way toward keeping your credit score healthy. For another thing, keep your balances low. Try not to incur too much debt on your credit cards, even if you have a high limit. Keeping your balances to less than 30% of your available credit will give you the most ideal debt-to-credit ratio. Third, don’t close a line of credit, even if you think you won’t use it anymore. For example, you may have a store credit card that you don’t pull out often, and you’re tempted to close the account. If you do, it can limit your length of credit history. The longer your credit history, the better – so do your best to keep those accounts open.