I use a secret algorithm + common salt that I can perform mentally to derive more-or-less unique passwords from service provider names. I don't trust any password manager, and this gives me the convenience of knowing my password across devices.
Not the person you were asking but I have a mental algorithm I use that produces unique salt for each website. When I run into issues about special characters not being accepted, I replace them with the number equivalent. For example 5 instead of %. It can be a pain to forget but there aren't many sites I use that are like that.
I still use a password manager I can reference if my algorithm isn't working for some reason.
