You would not believe how much smoother everything at work is when you learn to recognize early the signs that you're holding on to a bad opinion, or that you're headed towards a fuckup, and just saying it out loud.
The praising / agreeing thing is a bit more complex. I've noticed more recently that people tend to be quick to disagree but remain silent even when they agree with someones opinion.
Specifically calling out when you agree with an idea has some marvellous effects. The silent ones who also agree join in, people who disagree join the fray, and a rough consensus can be reached quickly.