When we're helping build trust in network relationships, we need to work from two distinctions: earned and unearned trust.
Unearned trust has to do with like and likeness. We naturally trust people like us and people we like. Closing triangles in ways that builds trust means helping people quickly find reasons to like each other and find ways in which they are already similar - in tastes, likes and dislikes, passions, perspectives, agendas, experience, values, and so on.
Earned trust has to do with making and keeping promises. Help people make and keep promises early on in order to help earned trust equity build.
After all, trust is the basis of speed and creativity.