How do founders find a co-founder they can trust?

A good co-founder can make a startup; a wrong one can break it. How do you find the right person?

Things that help:

• Look for complementary skills (e.g. builder + seller), not a clone of yourself.
• Work on something small together first before committing — a project reveals character.
• Talk openly early about money, equity, roles, and what happens if it fails.
• Shared values matter more than a shared idea; ideas change.

How did you meet your co-founder, or how are you searching? Share your experience.