Opinions are great, but don’t confuse them with facts.

I love working with people who can express their opinion but when a person presents their opinion as fact they’ve taken a turn down a frustrating path. If someone does this, call them on it. Ask if that's an opinion or fact. Opinions need to be flagged as such or they're a distraction for your team. They make people with opposing opinions dig in their heels for a war that can't be won without someone losing face.

Early in my career someone with more experience than myself called bullshit when I presented a ‘fact’ in a large meeting. We were working on a story-based game and I was telling the team how they had it all wrong when the savvy manager asked me how they could do it better. I knew a good story when I saw one but I had never written one. I knew nothing of the craft. Probably 30 people saw me learn a painful lesson.

Share your opinions and be prepared to acknowledge them as such or back them up quantitatively.