Secure your account
If you registered and NFID with Google, make sure your Google account is enabled with two-factor authentication.
If you registered and NFID with MetaMask, Internet Identity, or another crypto wallet, make sure you've stored that wallet's recovery phrase somewhere safe and accessible.
If you registered and NFID with device biometrics, make sure you remember your NFID number and add a few other devices for redundancy.
Security recommendations
We recommend you mainly use device biometrics, register a security key, and store your NFID number. Your NFID number is basically your username and therefore it doesn't much matter if people know what it is, and you'll need this number to re-authenticate on a computer whose browser history is cleared.
If your phone and computer both support biometrics, we strongly encourage you register the default browsers on both of those devices. Each browser on each device will need to be registered as "trusted" with NFID.
Recovery phrase
Although it's not necessary and although it's seen as a negative part of Web3, we still suggest creating a recovery phrase and keeping it somewhere safe until friendlier recovery options are made available.