Not all passwords are alike. Some are meant to be remembered (your password manager one, the mail account for recovering passwords, and/or a few more) while others can be stored in a password manager and just pasted in the password field without ever thinking on what they actually are.
The first group is the one that should be easy to remember for you but very hard to guess, specially with brute force/automated attacks (and if you want, have measures to be shared with your loved ones on your death). The xkcd approach is a good default for picking them, but you can do your own variation as long you remember it.
And the second one shouldn't be generated with a fixed schema that could be figured out if one or even several of the sites you have an account on gets hacked and retrieved your plain text password.
Is a just a encrypted file with a master password. Any mechanism that enables me to leave to someone else that master password (or a key part of it) would work.
