I would add ...fao: #reddit

+ if you want to start a subbreddit type group. 
Go to satellite.earth you can make one there (it's WiP - like everything on nostr).

Nostrudel.ninja is another client which does communities well, although I'm not sure you can actually Create a new community in there (?)

 

 totally! I forgot to add communities which are obviously appealing to reddit users. thanks!