A crew of nodding heads will cheer you straight off a cliff. Keep one friend who asks, ‘Wait, really?’

Enthusiastic company is dangerous in a specific way: it removes the friction that would have caught the bad idea early. Everyone is having a good time, nobody wants to be the one who slows it down, and momentum does the rest. What you need is one person whose approval you cannot assume.

Identify the friend who is willing to be briefly unpopular with you and run the big decisions past them. Tell them plainly that you want the objection, not the encouragement. Then listen to the answer even when the rest of the room has already agreed.