This is just common sense but worth saying: your team needs to have the same interests as you. A team with dissimilar interests will crumble in the face of adversity. Great startup teams have similar passions.
Compatibility
It’s simple: the best teams like each other. It doesn’t matter how well your skills compliment each other. If you want to rip each others brains out than it ain’t going to work. Compatibility beats out experience.
Experience
You’re passionate about the same things and you get along? Sweet! Now you can find people who’s strengths compliment your weaknesses. The goal here is to reduce redundancy. (Note: this can be accomplished through previous experience or dedicated learning)
Trust
No amount of social networking is going to guarantee that you’ll make a good team. You actually need to test the waters and try working together. Start small but make sure you test-drive your potential teammates.