At Disney, the Pixar Rule is the basic understanding that you cannot offer criticism without offering a suggested solution.
For example, if you work at Disney on the Pixar Team and you view the opening sequence of Cars 2 and you don't like it you wouldn't say: "The opening sequence wasn't as good as the first movie. You better change it."
That's simply offering criticism without focusing on concrete ideas of how to change it for the better.
Instead, you would say, "The opening sequence would be better if you didn't introduce any new characters and had Mater and Lightening zoom onto the screen straight away. The kids will love it. That's what they want to see."
In our church culture, we strive to offer constructive criticism.
Constructive criticism adds value to your feedback and can institute positive change.
Develop a culture that allows for honest criticism but also keeps the focus solution-oriented.