Reference values ​​for kernel and filesystem limits?

Question

linux

Good afternoon!
I ran into the too many open files error, googled and found a couple of articles:
https://galaxydata.ru/community/uvelichenie-limita...
https://ultra-technology.org/linux_for_beginners/t...
but everywhere they write differently , how to determine which value is the reference value, how to correctly set limits on system processes so that I would not have these errors not in nginx nor in redis nor in mysql, the limits themselves are configured using parameters already on the services themselves, but how to correctly specify the Linux kernel general meaning? at the same time, without laying down the server, since there was a case like the fact that an incorrect value did not allow the server to load!?