A lot of these communities already exist on several instances. If you're not already aware of https://lemmyverse.net/communities I encourage y'all to peep it
Chat
Relaxed section for discussion and debate that doesn't fit anywhere else. Whether it's advice, how your week is going, a link that's at the back of your mind, or something like that, it can likely go here.
Subcommunities on Beehaw:
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
Hmmm ...
Archery Motorcycles Old Photos in Real Life Spanish as a Second Language
I'm missing a lot of more specialised things, but these are pretty broad I think
I saw it sort of mentioned, but I think niche shitposting communities like the various okbuddy subs.
Videos/mealtimevideos was a big thing for me. They kept me entertained while I ate lunch, lol.
/r/chaosmagick
local geographic area. ought to be easy to create and find users. useful too!
I miss r/actuallesbians, r/MTF, and some obscure gaming communties like r/titanfall, r/Metroid and r/Earthbound.
Oh and the brainrot known as r/okbuddychicanery and r/anarchychess.
r/ImSorryJon
Eldritch horror Garfield is essential to any online community.
You're joking but currently a discord I'm in has a cult over a specific Garfield Minus Garfield comic, a cult that got genuinely rowdy when the comic stopped being posted.
All I'm saying, Garfield is probably an elder god
I'm probably only half joking. I love when people just do weird shit for the hell of it, it reminds me of the early internet. People doodling horrific Garfield content is weirdly wholesome and just makes me happy.