I have made it a rule to never deceive my dog, and she trusts me because it. If I pick up her water bowl to refill and clean it while she is in the middle of drinking, I make it a point to always give it back with fresh water. I have several water bowls around the house , and the one in my room only gets refilled when I see she is actively drinking from it.
She sees this removal of something she wants (and needs) as a good thing, because I have never deceived her. I always give it back.
If I say we are going for a walk or I grab the leash, we go for a walk. I try to not do things that she would interpret as something not intended. For example, grabbing the leash and not taking her out.
With dogs you become really mindful of your actions. They learn so many of your subtle non-verbal cues, that you start to notice how much your body speaks.
I often think about this, and it has been a valuable learning experience. If I ever decide to have kids, I will make sure that what I communicate (either verbally or non-verbally) is congruent with my actions. I believe that this, is the surest way to build trust.