SuperTD
Explorer
Keep Things Moving. We do this by saying "Yes, and..." to our fellow players. When a reasonable idea is proposed, we accept it ("Yes...") and add to it ("and..."). We don't shut down other people's ideas or try to tell other people how to play their characters unless they ask for help. It's discouraging to others and slows the game down.
How do your groups typically determine what constitutes a "reasonable" plan? No plan is ever perfect, and any plan can have flaws pointed out in it. I've been in groups which end up going back and forth on plans for way too long, as each time something is suggested another player will point out a flaw. Where do you drawn the line between a fundamentally broken plan, and a functional plan if everyone has a different threshold in mind where a plan's possible failings become an acceptable risk?