Gary Klein is a pricipal authority when it comes to intuition. He´s been studying nurses, figherfighter, jet pilots and the like for decades. He shared his insights in an article on Edge.org (link):
We learned about how he did the evaluation. He looked at several options, but he never compared them to see which was the best one compared to the others. He wanted the first one that would work, and he did this mental simulation. He did this imaging process for each one. That was the way he could evaluate one option at a time, not by comparing it to others, but by seeing if it would work in this particular context. Even though this didn’t have the outcome he expected, that turned out to be another part of the decision-making strategy that the firefighters were using.
It’s really a two-part strategy. The first part is the pattern matching to get the situation framed about what to do. Then the second part is this mental simulation to be able to evaluate and monitor an option to make sure that it will do a good job, and to use your experience. They would use their experience to do the mental simulation. In this case, the firefighter, his experience didn’t go far enough, and so his mental simulation didn’t work as well as he would have liked. Generally, though, it’s a very powerful technique.