As I've mentioned before, I operate under a high trust model in my classroom.
My students know that because I tell them. I set out some simple parameters at the end of my slide show presentation about what students can expect of the year.
One's personal integrity comes in part from one's trustworthiness - so, in my students' case, how much they keep to these simple guidelines.
So far I've been really impressed with my students this year.
They are well aware that when trust is broken, it is very very hard to get back.