I follow hashtags that I like and if I like a person’s posts I’d check their profile out and follow them. I also look at who interacts with my posts, and give them a follow as well, if I want their interests to show up on my feed. I also follow a couple of a.gup.pe groups. Bookstodon is a fun one, I got some cool suggestions there. They were also integrated with lemmy but I haven’t seen them work well here for now.