3-2-1 rule, 3 backups, 2 locations, 1 off-site

but it’s more like 3-3-2 for me tbh

+1 for addy . io, been using it for a while now and it’s nice to have unlimited aliases for free

I think you can whitelist websites to be exempt from deleting data from them on firefox too. I vaguely remember seeing something like that in settings near the “Clear Data” button.