Comment by mortenjorck

My model for people who "know what they're doing" is that they tend to have a well-organized hierarchy of rules. At the base are principles; at the top are opinions.

The foundation tends to be pretty simple, deeply held, and unchanging, while the higher levels are increasingly fluid and specialized. The higher you get on this stack, the more "making it up as you go along" it becomes, but every improvised part is perched on something more stable.

They key to "knowing what you're doing" is organizing this hierarchy well, having the right supports in place to successfully guide improvisation and course-correction while steadily fortifying the foundation.