I used to go with 'my gut', but as that did not go well as often as I would have liked, I started over-analyzing everything. That didn't really go well either.
So nowadays I am working on a new mantra:
"Less thinking, more doing."
I don't apply that to everything. Being an analyst in my day job, I still tend to apply some level of analysis to most decisions, but not nearly as much as in the past.