Unpopular buzzkill answer: You meet good cofounders from the good school you attend, your programming friends, and the top tech companies you work at. If you don't know any of those people, you don't have any good cofounder candidates and probably never will.<p>There's a reason "Poor kid starts a succesful startup" is much rarer than "Upper-middle class kid starts a succesful startup"
Don't be afraid to think outside the box. You likely have someone in your network who is a good fit. Especially if you're technical. Yiu don't need another technical founder, you need someone who's good at biz dev and marketing.
Through your network. I used to think networking was silly, now I am a cofounder.<p>If you live in SF, just go to meetups and coworking spaces and conferences and all that stuff.