​How do people here find trustworthy co-founders without knowing them beforehand?

I have a few startup ideas in different fields, especially around content creation. The main blocker is that i usually lack one of these 3: skill, capital or time, and some times all three of them. So I can’t realistically execute them solo.

I’m not looking for theory or generic advice I’d like real experiences. Where did you meet your co-founder, how did you test trust early on, and what signals mattered most in hindsight?

Failures welcome too. What seemed promising at first but later turned out to be a red flag?