Ask HN: How to Become a Technical Cofounder

I've got some startup experience + a few years of big co engineering, and am interested in exploring early stage startups. I'm craving the startup experience again, and would be interested in something early stage, but am skeptical that the economic side is worth it to join an early stage company as an employee.

What are things you'd recommend doing to develop skills to be a good cofounder? How would you go about finding opportunities?