How do you make good decisions in a team?

I recently submitted this post http://news.ycombinator.com/item?id=749810 but here today I'd like to ask you a practical question, unrelated to the software. I also hope the answers will be useful to all of us trying to make the right decisions. So, how does your team make decisions? What are the useful techniques that you use? For example, I've read a lot about the RAPID concept. Does it work? What other useful concepts do you know? Do you have any personal tricks? What is your earnest experience? Thanks to everyone who'll find a minute to share.