Consider using a credit card as opposed to a debit card when online shopping. There are laws that limit your responsibility in the case of fraudulent charges. The same protections may not exist for your debit card. Additionally, since a debit card draws from your own personal funds, there is the risk of fraudulent charges draining your money, which may leave you with insufficient funds to pay other bills.
It is a good habit to regularly check both your credit card and bank statements for fraudulent charges. If you find anything suspicious, immediately notify your financial institution and local law enforcement. Be on the lookout for phony emails requesting personal information. These emails may look legitimate, but they are an attempt to fraudulently gain access to your information. Legitimate businesses will not attempt to access this information via email.
Finally, if you do fall victim to online fraud, be sure to change your passwords immediately, using complex passwords that are impossible to guess. Also, be sure to use a different password for each account if possible. You may not be able to prevent all forms of fraud, but you can limit the damage by being smart and acting fast.