100% today I wrote one doing exactly this
There are ways. Commenting, hash tags (as nostr:npub1jmy8weweqzckna0amz7pn0uhhkxx693l7st23829ewmu43yvjsesfp6xcq mentioned) and IRL events.
It's possible that the data vending machines that nostr:npub1l2vyh47mk2p0qlsku7hg0vn29faehy9hy34ygaclpn66ukqp3afqutajft is working on could provide suggested follows based on notes or search phrases.
Discussion
Suggested profiles bases on search? Will keep an eye out.