Ask HN: How do you promote a GitHub project?

I'm working on an open source project on Github, and I feel it has value to others. I've rolled with Google Ads, Facebook pages and Slack channels - are there good ways to promote projects to the community? The project isn't picking up traction as much as I'd like.

I've done things already like paid people to try it out, and give me feedback, but I suppose the hardest part about getting the word out is getting the initial word out to others.

Do I keep on tooting this project until it takes off? Or are there established platforms that you know of that are good for launching open source projects?

I'm purposely not mentioning it here because I've already posted twice on the project in HN, but can mention it to you only if you are interested.