This question came from one of my formspring followers:
Q: Is there any way you can improve your credit score in a short time?
A: I'd generally say no, but really the answer depends on how much you want to improve your credit score and what you consider a short period of time.
Ruining a credit score usually happens over time, as either bad financial decisions or tough times erode your record of on-time payments and throws your debt-to-available-credit ratio out of whack. If it took you two years for your FICO score to drop below, say 600, don't expect it to be 800 in a year or less.
The things that help you improve your credit score the most are making payments on your debts on time and paying down the balances on any outstanding accounts you have, especially unsecured accounts like credit cards. The faster you can pay off any overdue or outstanding balances, the better chance you have of raising your score. But any blotches on your credit report, like delinquencies, bankruptcies or accounts in collection, can remain a drag to your FICO score for as long as seven years.
Do what you can to be responsible with your credit from here on out, but don't expect things to turn around overnight.