My rule is that I follow people who I have interesting interactions with in comments, or who have some opinions or viewpoints that I want to keep up to date with.
I've never understood the "follow hundreds of people" trend.
Discussion
I think it's well intentioned to make someone's initial timeline lively, but obviously there's no point having a super active timeline of 5 b/tcoin slogans and the same 12 'fuck the fed' memes (unless that's your thing lol).
And this is the advantage of algorithms. Having a "Discover" or "For You" page makes a lively feed for new folks, but there should be a linear, self-educated timeline to fall back on.