How can you improve your credit score?
It's very difficult to improve your score in the time between when most people decide to buy a home or refinance their mortgage and when they apply. So the short answer is, you really can't "on the spot." But there are strategies you can live with to make sure when you apply for a loan your score is as high as possible.
Make sure that the information each of the three credit reporting bureaus has on you is consistent and up to date. Order a copy of your credit report about once a year, and dispute any inaccuracies.
Unsolicited credit card solicitations in the mail don't count against your credit report, so don't worry. However, applying for credit, otherwise known as an inquiry, can negatively effect your score. Especially when multiple inquiries are placed in rapid succession. The best way to control this is to limit the number of credit applications you respond to. This holds true for credit card applications, car loan applications, and mortgage applications.
The two main components of your credit score are your payment history and the amounts you owe. It's never a good idea to take on more credit than you can handle. Bankruptcy filings and foreclosures, which can stay on your credit report for as long as 10 years, can also significantly lower your score.
Late payments work against you. It's extremely important to pay bills on time, even if it's only the monthly payment. A common misconception is that smaller bills do not effect your credit as harshly as larger bills. This is not true in nearly all cases.
Don't "max out" your credit lines. Since the size of the balance on your open accounts is a factor, lower balances are better. In other words, if your available credit card line amounts total $20,000 and the balance you owe on them is $20,000, you are using 100% of the line amount. The % of line amount you owe can negatively effect your scores if you are "maxing out". Conversely, the less you owe in comparison to the line amount can improve your scores!
