Common mistakes include focusing on rewards or an introductory rate while overlooking the standard APR, annual fees, balance-transfer fees and other charges. Applying for several cards at once can create multiple hard searches on your credit file, so check eligibility tools first where available. If you use a promotional offer, note when it ends and keep making at least the minimum payment on time, as missed payments can damage your credit record. Choose a card that matches your spending and repayment habits, and check the provider's full terms before applying.