I've read books about "Agile development" and I've read many, many articles about it, and I've read many conversations here on Hacker News on the subject, and I've engaged in many conversations with co-workers about "How to do Agile right" and yet out of all of that, the only rule I've found that easily transfers to every company, large or small, and which automatically improves team dynamics, is simply:

"Prefer small meetings over large meetings and prefer one-on-one meetings most of all."

Large meetings will inevitably include some people who don't need to be there, and who are therefore bored and disengaged.

By contrast, if you have meeting of just two people, both people are automatically essential to the meeting -- automatic because the meeting would not happen unless one of those people needed to say or ask something of the other person.