If you’re not using LastPass or 1Password as your password management utility, you’re internetting wrong. Seriously. They do all the work and generate random passwords for all of your sites.
If some holds a gun to my head and demands my bank account password, I’ll just have to tell him to shoot. It’s 12-16 characters long, random alpha-numeric & symbols interspersed. I truly have no idea what it is … but LastPass knows.