You have a low score, so I’m going to guess you have some charged-off, unpaid or seriously delinquent accounts on your credit report. The damage to your credit score has already happened. What you can do initially is make sure the negatives reported on your credit file are accurate and not out of date. Look over your credit reports, and dispute any negative items that you don’t think are yours or are more than 7 years old. Once you have ensured your history is accurate, you can work on adding new, positive data.
All credit scores are based on the contents of your credit reports. Any errors in those reports can cause undeserved credit-score damage. They can also indicate fraud. So check your reports, dispute any errors you find, and take steps to protect yourself from identity theft if necessary. In particular, look for collections accounts, public records, late payments and other bad credit-score influencers.
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.