Check Statements
Don't wait for your bill to come at the end of the month. Go online regularly during the holiday season and look at electronic statements for your credit card, debit card, and checking accounts. Make sure you don't see any fraudulent charges, even originating from sites like PayPal. If you do see something wrong, pick up the phone to address the matter quickly. In the case of credit cards, pay the bill only once you know all your charges are accurate.
