Bankrate put out a list of tips for increasing your credit score. Some of these are so obvious as to be almost stupid. Others though are good advice. My favorite is this: if you're going to make a few credit inquiries (searching for the best car loan for example) make those inquiries in a very short period of time. Don't spread them out over weeks while you casually look. Within a certain tight time frame those inquiries will be counted as only one, whereas the same four inquiries spread out over nearly two months may count as all four.

Go here to see their list of tips.