I set up /--.pdf
to start with. I find that for my yearly document amount, there is no value in adding more than one level of hierarchy. File browser search tools are easier than more hierarchy for the last bit.
I think I will switch my default path to be <correspondent>/filename.pdf
(with filename as above). I think organizing by correspondent will give a more meaningful sorting for "manual" access than sorting by year.
For files which are strongly tied to a date, as documents in Paperless pretty much always are, I like to have a YYYY-MM-DD
(ISO-8601) format date as the first element. This gives a nice chronological sorting.