Once you have your credit reports, read through them completely. If you have a long credit history, your credit reports might be several pages long. Try not to get overwhelmed by all the information you're reading. It's a lot to digest, especially if you're checking your credit report for the first time. Take your time and review your credit report over several days if you need to.
Next, estimate your monthly spending habits for other expenses such as gas, groceries and entertainment. Create a limit, based on your income, of what you can spend in each of the different categories of expenses. For example, if you tend to spend $400 a month on groceries, try to stick to $300 a month on groceries by making changes like buying generic brands, using coupons, and resisting impulse purchases.