Diagnose the real issue
Separate symptoms from the operating, governance or ownership problem creating them.

The CEO owns the decision. The Shadow CEO makes certain it is informed by experience the executive may not yet possess.
A capable executive can still face a transaction, board conflict, capital decision, leadership failure or company transition they have never managed before. That is not a weakness. Pretending otherwise is.
Separate symptoms from the operating, governance or ownership problem creating them.
Clarify the available choices, the risks attached to each and the information still missing.
Turn the decision into specific actions, accountability and a timetable.
Anticipate the second-order effects on the board, management team, capital structure and enterprise value.
A Shadow CEO does not run the company. The CEO remains accountable. The value is experienced judgment before an unfamiliar decision becomes an expensive lesson.