Riddle me

Having written essays on various concepts, I have come to the realization that having the ability to percieve, select, and enable the best questions in a situation will often give you just the right perspective. And of course "right" is relative. In particular, given the fact we're talking about general situations, this is the only time where right is relative.

Kind of like observing the generality "all generalities are false" as true, therefore proving itself false.

So the question is, what questions best help you see the information you are currently gathering?
Are there guidelines for selecting questions?
Are there guidelines for always picking the best questions?
Is it instead, a response kind of thing, where you start with a powerful lead question, and the result(s) from that question direct you intuitively to the answers your situation requires?
Are there ever questions that are so good they are never answered?