Stephanie Vozza has a fascinating post at FastCompany about intuition. Drawing on the word of William Duggan, author of Strategic Intuition: The Creative Spark in Human Achievement, she identifies three levels of intuition and their sources:

Basic
Expert
Strategic

Basic tuition is that feeling one gets, a gut instinct to do or not do something. Expert intuition arises from experience. In certain situations one just knows what needs to be done because one has been in similar situations before and knows what works, and what doesn't.

I was most intrigued by Vozza's explanation of strategic intuition. She writes:

Strategic intuition is different than the first two because it happens when thoughts in your brain come together to provide a solution to a problem you’ve been considering for some time.

What I found interesting about strategic intuition is that it is ephemeral. "It’s important to capture these thoughts because the brain is so efficient at wiping them away." Quoting Duggan's work, Vozza writes, "If you don’t catch it right away, you may lose it.”“If you don’t catch it right away, you may lose it.” This is certainly true in my experience. I've had many a good insight or intuitive flash of a solution to a problem, only to forget it quickly when I didn't record it somewhere easily retrievable for later reflection.

Vozza's article also offers a list of helpful questions one can ask one's self when determining whether or not to trust one's intuition:

"Do I feel good around this person or choice?"
"Does this person or situation give me or take my energy?"
"Do I feel empowered or disempowered?"
"Am I going toward an adventure or running from fear?"
"Am I listening to my lessons learned from the past?"
"Would I make the same choice if I had a million dollars in my pocket now?"
"Do I feel respected and valued?"
"Am I trying to control the situation or am I leaving room for expansion?"

I think I'd add one more to the list: "Does the proposed action align or conflict with my core values, with my best self?"