Keeping Systems up-to-date.
Everyone should know the importance of keeping your operating system, and software, up-to-date. Even with the amount of information on the subject, there are still many that allow this task to slide for excessively long periods of time. That is a very, very, bad thing to do, given the volume of malicious software that we are constantly bombarded with.
While I am not personally a fan of automatic updates, that is a far better choice than not installing updates at all. If you find that you are not taking the time to apply the patches and updates, then, by all means, configure automatic updates, and let the system do it for you.
While automatic updates involve an amount of risk, it is much less than the risk run by not having current fixes and patches applied. My preference is to periodically (and frequently) manually install the updates. Manually installing allows me to check for known issues regarding those updates, and make the decision to install a particular patch, or not. This approach does take some dedication on your part, though, and as such is not for everyone.
Whichever method you choose, be sure that your systems are updated with the current patches and fixes. Otherwise, you are running the very big risk of waking up to a nasty situation, in which your computers have been compromised, or are being held for ransom.