Here is a list of things that will lower your credit score. This is an excerpt from:
5 credit score killers By Blake Ellis, (CNNMoney.com)
FICO focuses on five categories when calculating your score: How much debt you have, your payment history, your debt utilization ratio (how much you owe in relation to your credit limits), how far back your credit history goes and your mix of various types of credit.
Here are a few things that can wreak havoc on your score and wreck your chances of getting an affordable loan:
1. Making late payments
2. Carrying a big balance
3. Closing a credit line
4. Opening a credit line
5. Defaulting
Read more here: money.cnn.com
