I use the technique of taping a microsd card with copies of my passport, credit cards, 2fa backup codes, etc, encrypted; along with a $100 to the bottom of my insole inside my shoe. Put them in a little "crack sized" ziplock, add lots of gaffers tape (so if you take the insole out it's not obvious, plus makes it a bit waterproof) and if I ever get mugged, I have enough cash to get a cab (or depending on where I am, pay a bribe) and then find a computer I can use to get my info and figure out next steps.
Normally carry a yubikey with me (2, in fact, one on me, one in my big bag at my hostel / hotel). But if I get mugged between airport - hostel, then at least I have the shoe backup.
A 3rd level is that my parents have a yubikey and 2fa backup codes for me. They dont have my passwords, but in a pinch, I can call them to read me a code.
Not my idea. You can have a lawyer that has access to all your passwords, and designate a list of trusted people that can access them in an emergency.
If something happens, your friend calls the lawyer. The lawyer calls the other friends and if enough concur releases your passwords.
Depending on how technical you and your inner circle is you can even have whatever secret the lawyer holds encrypted and a key preshared with your friends so that the lawyer cant use it or the secret is irrelevant if it leaks.
This is of course more relevant in a you drop of the face of the earth, or you are wrongfully or rightly arrested kind of scenario.
Keep an eye on FRAM storage devices. Currently you can buy a USB stick with 8 KB of storage, but that storage is designed to last 200 years (and should at least survive a few decades). You can even recover the data off it with a soldering iron and a steady hand if needed. Would be a neat solution for keeping a backup code in a safe long term (maybe once the price drops to be competitive with a laminated sheet of paper)
Normally carry a yubikey with me (2, in fact, one on me, one in my big bag at my hostel / hotel). But if I get mugged between airport - hostel, then at least I have the shoe backup.
A 3rd level is that my parents have a yubikey and 2fa backup codes for me. They dont have my passwords, but in a pinch, I can call them to read me a code.
Very open to ideas on things to improve...