Success really depends on the pool you're drawing from. A public open invite on FB is one of the hardest approaches. Kudos to the people who can pull it off.
The easiest for me was using my city's discord server as a launch pad for running book clubs, coffee meetups, and hikes. After a few successes, it's easy to gain a reputation for making things happen and it sort of snowballs from there.
It is also important to not become bitter when you fail. Starting up community activities is hard. It is somewhat like seeding servers in classic multiplayer games like CS1.6.
