There are a lot of things that have been lost to us due to the interposition of a monotheistic Christian cultural overlay in Hellas between the end of the Hellenistic/Roman periods and the modern era. This leads to people not knowing things that they wish they could find out more about.
In my case, dealing with Poseidon, there is not much available on how he was worshiped in the pre-Christian era. Still less information is available concerning how he was worshiped in places like the islands of Crete and Cyprus as well as in places like Sparta.
What I would like to know is if there is any reconstructed/revived material that addresses these things. It’s hard to know the best way for ME to worship him without at least some idea about what our forebears did.