More often than not, company culture is idealized.
A group of managers sit down and write about their ideal company. And of course, everybody wants an honest working environment where feedback is given regularly, it does not matter if they have never delivered honest feedback once in their careers, and the very idea of doing that scares them.
Next time you are having a conversation about culture, think back at what you and your colleagues have done so far. Certainly write down your ideals, but then challenge the group to identify and narrativize some concrete example that embody the ideals.
If finding those is not a problem, you are on the right track. Own the examples and spread them internally and externally, as they will resonate with people far better than words that have been inflated.
If finding examples is proving difficult, that’s the first symptom that your attempt with culture will fail. You can either proceed with a culture change (changing the way things are done), or try to find ideals that better reflect what is really happening (and for which you have good examples).