Im currently figuring this out myself. So far Ive been trying to establish presence on HN and Reddit but it's really tough as a new user. I think that as you begin to gain credibility in these spaces, it gets easier to get exposure because you're actually seen as a real user. Just my two cents.

You work on things you know something about, and things that people want to talk about. And you go where people are (meetups etc).

Or offer something for free and hope that people reach out to you for conversations.