Of all the people who use introspection, probably the most interesting are the poets. Their raw material is their conscious thoughts. How they use those thoughts varies but it is rarely confined by aspects like logic or usefulness or accuracy. No, all that matters is affect and beauty in the language used to dress those thoughts.
MindHack recently had a posting including a quote of Ted Hughes (here)
There is the inner life of thought which is our world of final reality. The world of memory, emotion, feeling, imagination, intelligence and natural common sense, and which goes on all the time consciously or unconsciously like the heartbeat.
There is also the thinking process by which we break into that inner life and capture answers and evidence to support the answers out of it.
And that process of raid, or persuasion, or ambush, or dogged hunting, or surrender, is the kind of thinking we have to learn, and if we dont somehow learn it, then our minds line us like the fish in the pond of a man who cant fish.
In my mind, I contrast this reliance on introspection with the attitude of the master of martial arts. The person looking for reliable action, fast, accurate and appropriate, needs to avoid introspection. They need to practice until meta-cognition is not required and, in fact, is in the way. Their thoughts go on all the time consciously and unconsciously like the heartbeat, but there is a wall against introspection breaking into that inner life.
There we have the extremes of introspection.