The decisions that justify the level are the ones made with bad data and no time. Everything else is execution.
The bad-data case is the one designers are least prepared for. School and the early career train you to gather signal. The promotion to senior tells you the signal is thinner than you expected. The move to staff tells you that for the questions you are now being asked, the signal is often absent. By principal, the absence is the job. You are not being paid to wait for better data. You are being paid to make a defensible call without it.
The framework I have settled on is smaller than I expected when I started looking for one.
First, name the cost of being wrong in each direction. Some calls are reversible at low cost. Make those fast. Some calls are reversible at high cost. Slow down, but only as much as the cost justifies. Some calls are irreversible. Those get all the time you have, even if that is two hours.
Second, write down the bet. Not the decision, the bet. “I am betting that the user will read the second line of this onboarding if the first line earns it.” That sentence is testable later. The decision wrapped around it is not.
Third, time-box the deliberation. The decision you would make in two hours is usually the decision you would make in two days. The extra time mostly buys anxiety, not signal. Set a clock. When it rings, commit. The discipline is to actually commit, not to extend.
Fourth, ship the decision with the bet visible. The team needs to see what you are wagering on. This is partly humility and partly insurance. When the bet pays off, the team learns the pattern. When it does not, the team learns the cost. The decisions made silently teach nothing either way.
The honest limitation is that this framework breaks when the cost asymmetry is genuinely unknown. Some decisions are made in fog so thick you cannot see which direction is reversible. In those cases the framework does not help. Experience does, and even then incompletely.
The shift is to stop apologising for decisions made under uncertainty. They are the work. The apology is a tell that you have not accepted what the role asks of you.