Never, ever ignore your monthly statements. Not knowing how much you owe to the bank can very quickly land you in a lot of trouble. Be aware of your monthly statements to know where and what you're spending on, if you're being charged for something you didn't purchase, and to keep a check on your budget. It is always important to know where you stand and the monthly statements will help you get a grip on things.
8. Using card to withdraw cash
ATM is considered 'cash advance' by the banks. It's considered more like a short term loan. A loan doesn't come without interest and cash withdrawals attract a mammoth interest rate. So don't even think of touching your credit card at an ATM unless it's a matter of life and death. Stick to your debit cards otherwise.