I recently found some people to collaborate with

One was through GitHub where I started talking to a developer after contributing some fixes to his project which got the ball rolling on another endeavor that we're both very interested in creating

The other was through a forum where some users are creative technical types, so giving feedback opened the doors for collaboration

The idea that attracts others is the idea that is well-communicated. So start talking about specifics in the open. You may be surprised at the responses