Time it takes: 8 minutes
Dial your issuer and ask for a lower rate. If your credit score tops 720, do not be satisfied until your rate is less than 10%, says Curtis Arnold of CardRatings.com. Your biggest weapon: Make it clear that you'll stop using the card if the issuer refuses. Our reporter, helped by the fact that she's been a good customer for seven years, got the rate on her Discover card cut by four percentage points.