I always like forum setups where you had limited posting privileges until you'd had a couple of posts. Usually, they'd have an introduction category where you could post, and then comment on some other users' posts, to get your post or reputation count high enough to unlock the rest of the board.

Most Lemmy sites are small enough to have a local introduction community or other 'free' communities for newbies to dip their toes and acclimate. They'd be good places to centralize posts on how all of this works, too.

Wouldn't scale to large servers, though.