There's a really good community feature on here called groups. It works like this:

1. Follow a group's account
2. You will start seeing posts on that topic
3. You can post to the group by @-ing it

For example, follow @tea to see posts about tea.

It's more powerful than following hashtags, as all group posts are actively pushed to all of the group's members. No one misses anything.

Find out more at https://fedi.tips/how-to-use-groups-on-the-fediverse/, and I've curated some nice active groups at https://fedi.directory/tag/fediverse-groups/