Learn to trust and be trustworthy. When you treat someone as if they are being dishonest, you will train them to be. It's more powerful to treat someone as if they are being honest, and you will train them to now be honest, even if they weren't then.
I always have issues with trust. I'm a New Yorker... Really, I think trust is something that comes from the gut. And I think you have to - it's probably the worst advice to give people - but I think you gotta trust people from your gut.