Please revise the following paragraph by incorporating a bulleted list with category headings:
There are many people today who want to improve their credit scores. Some simple tips for bumping up your score are obvious. For one thing, you should immediately fix mistakes. If you check your credit report (and you should at least once a year) and there are errors, you can dispute these and have them investigated. Another way to improve your credit score is to pay on time. At least 35 percent of your score is a direct result of your payment history. Next, you should make an effort to lower and reduce your balances. It may be difficult, but you should keep your personal credit balances as low as possible. The less you're using, the better for your score. Finally, making a habit of keeping older accounts will improve your score. This means that you should keep your older cards so that you have a longer history to share. It also shows stability.