Develop a Good Credit Score

To establish and maintain a good credit history, you should:

Pay your bills on time.
Try never to exceed more than 20–30% of your credit limit. For example, if you have a credit card with a $1,000 limit, you should carry a balance no greater than $300. Less is better!
Limit the number of cards you have. If you are just starting to build your credit, keep only 1–2 cards. As you establish credit, you can increase that number if necessary to 2–4 cards.
Watch your number of credit inquiries. Don't open several new accounts in a short period of time.
Use your credit card at least once every three months. It is to your advantage for your credit report to reflect current responsible use of your credit accounts. Charge what you know you can afford and pay it in full when the bill arrives.
Check your credit report annually at AnnualCreditReport.com.