Mastodon could definitely do with some more discovery methods. Hopefully something like bluesky's starter packs get implemented eventually (but I understand why they aren't rushing it, there are abuse risks).

Best approach for now on mastodon is to follow all the hash tags you're interested in, and then follow everyone in your feed who posts anything interesting. Takes a few weeks to ramp up, I guess. My feed got good once I was following around 1k users. You can always unfollow if someone's annoying.