Tips for good credit:

Know the terms of your credit card agreement

Understand the terms of agreement before you accept a credit card Set aside money each payday for emergencies Set a monthly limit for charges and stick to it Shop as carefully with a credit card as you would with cash Don't take on more monthly credit payments than you can afford Pay bills promptly to avoid penalties and to keep finance charges low If you charge day-to-day expenses, make sure you pay off enough monthly to keep your credit card from ballooning Keep credit card information (including phone number of issuer) in a safe place in case your card is lost or stolen Keep copies of sales slips and compare charges when bills arrive. If there is a mistake, call your CC Company right away.

Tips for maintaining good credit

Pay at least the minimum payment due on time every month Don't overextend yourself. Don't spend more than what you can repay Spend as you earn. Don't borrow in anticipation of future earnings Avoid transferring balances unless you are really getting a better interest rate Notify creditors when you move, so your bills will arrive on time and you can pay on time. If you don't get your bill, you are not excused from making the payment

Source: Citibank: Use Credit Wisely