Contact your credit card company to reduce your credit limit if it is higher than necessary.
Understand that low introductory rates are for a limited time and can be very high after that time is up.
Avoid “free gift” or percentage off offers for credit cards. These may be predatory lenders, or just a store card which typically have higher interest rates.
“55% of college students acquire their first credit card during their first year in college, and 83% of college students have at least one credit card.” Senator Akaka, Credit Card Minimum Payment Warning Act, May 21, 2004.