I use https://lemmyverse.net/ since I’m on a smaller instance and a lot of communities just don’t appear for me until I’ve manually searched for them.

https://lemmyverse.net/communities

This is a good website if you know what you are looking for

i took a stranger approach. i went to ”all” and viewed new, doom scrolled and added every community i found. then did same with ”active day”, ”active month”, etc. and just kept choosing new sorts and doom scrollin.