Habits are hard to change, but you should try your best to avoid these bad security practices:

• Never send passwords, personal data or financial information via plain text email.
• Do not access networks or other systems for which you do not have authorization, even if you have somehow obtained certain login credentials (username, password). This does not mean that you have been authorized to use them.
• Do not install suspicious add-ons and software updates.
• Be wary of suspicious links you received via email, no matter how interesting the message may seem. It is better to be safe than sorry.
• Avoid using public or unprotected computers.
• Avoid using other people's mobile devices.
• Don’t write your passwords on a publicly displayed Post-it note. Seriously, don't!
• Don’t use the names or dates of birth of people close to you as passwords.
• Don’t leave your devices unattended and unlocked.
• Don’t ignore suspicious activities - sometimes it’s better to be paranoid.
• Do not use pirated software, i.e. software packages that have some type of security or product registration circumvention built in. If you do not want to pay for software, look for a free and open-source alternative.
• Don't live in your comfort zone. Sometimes it is worth investing a little time and effort and learning the basics of how to be safe on the internet.