The six thinking hats is an excellent framework by Edward de Bono for product managers having discussions that are more structured and balanced. The idea is that all thoughts and statements can be put in one of six categories. As a pedagogical device, the categories are represented by hats of different colors.
We all have opinions. And when our opinions are not taken into account we felt not only personally ignored, but also that the company is missing out. But from the employer's perspective, what is really an opinion. And when does it make sense to take it into account?