Minimize Credit Inquiries
Encouraging too many lenders to look into your credit by applying for too many loans and credit cards in a short time is one sure fire way to lower your credit score. You should also avoid giving a lender your social insurance number as that can also be easily procured to make a credit inquiry.
If too many inquiries are made into an account in too short of a period of time it sends a signal to the lenders that you may be out of money. It is the classic behavior of someone who is overextended in terms of debt. The FICO scorecard reaction to this is of course a lowered credit rating.
The exception to this piece of advice is when you apply for mortgage or car loans in which case you have a 14 day period in which to make ALL inquiries in order to acquire the best interest rate. The cumulative number of these inquiries are only marked as one black mark on your credit as long as you manage to do it within the two-week period.
The fact that too many hard inquiries can severely damage your credit score is why it is also a good idea to not fill out every credit card offer or application you are sent though the mail, offered in a mall or retail store. Although you may save money on purchases, the credit inquiries that culminate as the result of applying for a lot of credit cards can really add up. The lowered credit score that is the result it can make something really important and that really matters such as a mortgage more expensive.