Make passwords looooooong ...
The longer it is, the harder it is for a hacker to crack. It takes less than one second to crack a three character password. A good rule of thumb to follow for password security: anything 16 characters or more is considered to be a strong password.
And don't use "password123!"
Do NOT reuse passwords. EVER.
Be sure to change your passwords on a regular basis to help keep your information fresh and reduce the chances of one of your passwords becoming exposed.