Given today’s tough economy, it’s more important than ever to have good credit. So what should you do if you’ve made a few mistakes? The solution for fast credit repair may vary depending on the problem.

But most experts who know how to repair credit will tell you that you need at least one of these three: A change in behavior, a bit of effort, and time. In other words, self-help credit repair doesn’t happen overnight.

The good news is that everyone can learn how to repair bad credit. If you’re patient, consistent, and committed, applying these tips could make a positive difference for your credit score:

Having late payments is the single biggest cause of bad credit. Just a couple of late payments each year can have big negative effect on your credit score. And unfortunately, with our hectic schedules, it’s also the easiest “credit sin” to commit—especially if you’re juggling multiple accounts.

If you’ve had only one or two late payments, don’t be overly concerned. Instead, take steps to make sure that all of your future payments are on time. You may consider setting up automatic payments through your bank, or programming reminders into your calendar. Over time, a positive history of timely payments will gradually “erase” the impact of your late payments.

On the other hand, if you’ve had more than three late payments in the past year, you may wish to submit a letter of explanation, which will be filed with your credit report. This will not change the facts in your credit history, but it may provide potential creditors with added perspective about what led to the late payments. Of course, you’ll also need to take steps to ensure that all of your future payments are made in a timely manner.

Don't think this is the only tip for fast credit repair.

Although an extensive credit history is a plus, having a poor debt-to-income ratio can hurt your credit score. The higher your level of debt as compared to your income, the less disposable income you’ll probably have. This worries lenders because it’s more likely that you won’t be able to meet your debt obligations, should an interruption in cash flow occur. As we saw in the previous section, there’s no quick fix to the question of how to repair credit.

If your debt-to-income ratio is too high, you will need to reduce your debt, increase your income, or both. In some cases, you may be able to work with a credit-counseling firm to have your debts restructured. But most of us just have to knuckle down for a year or two to make a dent in our debt.

As a rule of thumb, most experts on fast credit repair recommend using less than half of your available credit. If you currently exceed this level, try to cut back on non-essential purchases—and pay more on your credit cards—until you’ve reached a more ideal ratio of debt and income.

Most consumers are unaware of the fact that every time they apply for a new line of credit, their credit score is assessed a small penalty.

This doesn’t mean that you should avoid applying for credit altogether; a credit inquiry every now and then shouldn't be a problem. But frequent requests for credit can be. Lenders and credit bureaus may interpret frequent requests for credit as a sign of impending financial trouble, and may be less likely to consider you a good credit risk as a result—especially if you’ve recently been turned out.

If this applies to you, the solution is simple: Stop applying for additional credit for at least one year.

Did you know that the average age of your credit cards and loans can affect your credit score? This is an important fact to consider if you’re wondering how to repair bad credit.

When the credit bureaus look at your credit report, newer accounts are given less consideration than the older accounts. This is because older accounts contain a longer payment history and thus provide a more complete snapshot of your credit usage and your timeliness in making payments.

This is one reason the average age of your accounts can play a role in determining your credit score. Consumers who have an older average account age are viewed more favorably by the credit bureaus than those who have several new accounts, regardless of the payment history.

So, what should you do if you’ve recently opened several new accounts to save 10% on your purchases? What’s done is done. Closing the accounts won’t have a favorable effect on your credit score, so it’s best to leave them open, make regular payments, and hold off on opening any more accounts for at least five years, if possible.

We’ve saved the worst for last. Bankruptcy may seem like an easy “out” to debtors who are in over their heads, but it really should be viewed as the solution of last resort.

Declaring bankruptcy will freeze your finances for at least two years. And even when you are able to obtain credit again, it will be at much higher rates than you would have qualified for before.

Bankruptcy will stay on your credit report for at least seven years (sometimes even longer), and could adversely affect your credit score for more than a decade. Also, consider that many employers run credit reports on prospective employees. This could put you at a disadvantage against other equally qualified candidates.

Most experts who are familiar with fast credit repair will tell you to avoid bankruptcy at all costs. But if you’ve already taken that step, don’t despair. You can still rebuild your credit—though it will take time. Work with a credit counselor who specializes in how to repair bad credit, and follow his or her advice to the letter. Within a few years, you can be back on track with a stronger credit score.