My Fediverse Advice:

* Follow more people. No, even more people than that. Basically, if you find a real person and their posts are good follow 'em
* If you get a good reply to a post boost it. If you make a good reply to a post boost it. Replies are not visible in the feed unless you do this. As long as the post is an OK start to a conversation or interesting boost it.
* Write thoughtful replies. And if you put effort into a reply boost it or probably only the people tagged will see it.

@futurebird A personal variation/improvement on the first rule that I don't often is "follow and filter". There are active accounts that boost a lot or post on multiple topics, some of which might not be interesting. Instead of unfollowing, a first step is to try and install filters to remove uninteresting/unwanted posts. That also helps keep the feed managable.

To help out with this on the other side of the coin, it is useful to tag posts properly and with common hashtags.