I'm a big fan of the "wisdom " check before players do something that seems, to me, completely stupid. Like, hey, before you set out to storm the castle, roll your highest knowledge skill.

Tactics, architecture, history, etc, all good. But any success on any skill (or even, literally, Wisdom if nothing else) gets you a little hint that this is a terrible idea.

"OK well, as a Baker, you understand that the huge wagon pulling 500 loaves of bread into the castle means there must be an enormous amount of guards. Since you got a natural 20 on your Cooking check, you can estimate the number precisely to around 150. Even if they weild the baguettes as weapons, you are certain they will defeat you."

And then, most parties I've played with will then begin formulating their plan to sneak in on the bread wagon, which is a much funnier story. Or they'll complain that they meant the druid should cause a storm to distract the guards or something like that. It's kind of amazing how often these bad plans arise from a miscommunication.