Never share passwords with anyone, not even your spouse. Even if you trust the person completely, do you trust that they'll never be lured by a spear phishing attack that may have you as the actual target?

Don't reuse passwords, and rely only on strong passwords, meaning long passwords with numbers, capital letters and special characters. You can either develop mnemonic tricks to remember these, or use password management tools like 1Password or LastPass.

Turn on enhanced authentication and security when it's available. For instance, Facebook, Google and others offer enhanced security features, such as SMS notifications if an unknown device attempts to access your account.

Use tools you already have, such as time-outs and screen locks on mobile phones.

Pay attention to your social interactions. Be careful not to broadcast your date of birth, anniversary, name of your high school or other identifying factors that could allow hackers to pass through challenge questions.