Hint: it's not by using 30-character alpahnumeric+symbols passwords.
First - low tech, highly effective:
https://www.abqjournal.com/922376/community-college-student-admits-role-in-hacking-top-u-s-officials.html
Both Forbes articles are well worth reading:
http://www.forbes.com/sites/laurashin/2017/01/04/7-ways-to-make-yourself-hack-proof/#6fbb09d5647d
and
http://www.forbes.com/sites/laurashin/2017/01/04/be-prepared-the-top-social-engineering-scams-of-2017/#6cbb3621064f
7 Ways To Make Yourself Hack-Proof