I have only middling success with this.
For many years I thought that my eclectic and rather agnostic spiritual path gave me an edge in this area, but I think it was simply an area of strength during a particular phase of my life. I had faced certain fundamental questions, judged most of them unanswerable and others negotiable, and was comfortable with that. End of issue.
Except that I'm not like that in most other areas of my life. I may choose to transgress certain rules or boundaries, but I want to start by knowing what they are so that my transgressions are conscious and deliberate. I want maps, schedules, and directions when I begin, even if I choose to ignore them later. I don't feel any need to make my interpersonal relationships conform to cultural norms, but I want to be clear about where I stand with family and friends so I understand the boundaries and expectations and commitments, lest I violate them without intention.
All in all, I suck at ambiguity. It stresses me out, even paralyzes me in some cases.
Working with Ereshkigal doesn't seem to help. One of Her characteristics is upholding boundaries. Maybe that's one of the reasons we get along so well.
But much of what I'm doing now involves ambiguity, involves pressing toward goals in unfamiliar territory where I don't have instructions. My inner world work as a priestess can involve significant ambiguity. It's often a difficult emotional and psychological stretch.
And I have to keep reminding myself that growth almost of necessity involves ambiguity. If I never get into uncharted territory, I'm not going to continue my growth as my own person.
As with so much else, I consider self-awareness to be critically important. Being aware of the challenges presented by ambiguity is half the battle of coping with it constructively rather than instinctively reacting with withdrawal, being a control freak, or etc.