1)Facebook Groups. It's a little bit tough but I had some success there. Groups like Startups Jobs, Jobs in San Francisco, Remote Jobs in Startups etc.
2) Freelance Marketplaces. Upwork (upwork.com), Freelancer (freelancer.com), and Periodix (https://periodix.net/). It's a new service but helps me a lot already. I found this service in Reddit and didn't expect great results. But I found something reasonable for myself and be hired fast.
3) Linkedin. Recruiters write me every day.
4) Local Websites. I check every day local job boards to find a local project. Because it seems faster to be hired.