3. Keep the lowest APR card
When you destroy your cards, remember to keep the lowest APR credit card with you. It will help you during emergencies. Define what an emergency means to you and use it in only those cases. And, since it does not carry much of an interest rate, at the end of the month the bill will not agitate you. If you tend to spend a lot with it too, then keep it in a safe place, instead of your wallet.