Algorithmic passwords. Come up with an algorithm a(website, rules) that you can remember and that generates unique passwords per website. Store the rules (length restrictions, special character restrictions, number of times the password has changed, etc) in a google doc or something. Print out your algorithm on a physical piece of paper and put it in a safe place for after you die and people need to access your accounts. People always poop on algorithmic passwords, but so far no one has hacked my brain and gotten the algorithm unlike all these other cloud-based password managers that keep getting compromised.

Plus, if my phone or my yubikey or whatever is stolen in a foreign country I'm not SoL because the algorithm is in my brain and the rules are public knowledge.