I know there are sites out there designed for finding Lemmy communities that aren’t within your instance but it can be a difficult to find some more abstract ideas.
For example a community for goofy joke “million dollar” ideas like a gag gift for suburban moms that consists of divorce papers in a red frame that says “Break in case of emergency” or a gun that plays the Danny Phantom lines “He’s a phantom” or “I’m going ghost” whenever you pull the trigger.
well, if you cant find it i think you’re required to make it.
i like to surf active new queues, so when looking for new instances/ communities i sort by volume of active users (MAU) on fedidb.org and then again in the individual instances by posts in their community search. this gives a good idea of general activity type and volume on the instance.
if you really want to find those niche places that might not have much traction youre stuck using those fediverse search sites