Hobson advised people to use cash for smaller purchases. People spend 12 to 18 percent more when they use cards versus cash, because when they use cards they don't actually see the money changing hands.
If you do use credit cards, pay your balance in full.
Here are some extra tips from Mellody Hobson:
If you have reserved a hotel on your card, try to use that same card to make the final payment. If you use a different card – or another payment method – to make that final payment upon checkout, the blocked amount may stay on your account longer.
Never opt-in for overdraft protection for your debit card.
Report a lost or stolen debit or credit card right away. Make sure to save your debit and credit card receipts and compare them to your monthly statement to ensure there are no erroneous or fraudulent charges.
If there's a PIN number associated with your debit card, don't ever share that number with anyone.