The best practice for password security among the options provided is:
changing passwords often.
However, it's worth noting that while changing passwords regularly is important, it is also crucial to create strong, unique passwords for each account and not to share them, even with trusted individuals. Using real words in passwords can make them easier to guess, so it’s better to use complex combinations of letters, numbers, and special characters. Using the same password for many sites is generally not recommended due to the increased risk of a single breach compromising multiple accounts.