Brett M. Kavanaugh, The Judge as Umpire: Ten Principles, 65 Cath. U. L. Rev. 683 (2016).
First, and most obviously, a good judge, like a good umpire, cannot act as a partisan.
Fifth, at the same time, to be a good judge and a good umpire you have to possess some backbone.
Sixth, to be a good judge and a good umpire, you have to tune out the crowd noise.
And from the abstract:
Judge Kavanaugh discusses the notion of Judges as umpires and sets forth ten principles that are vital for an impartial judiciary dedicated to the rule of law in our separation of powers system. According to Judge Kavanaugh, Judges cannot act as partisans, must follow establish rules and principles, and must strive for consistency, not only in terms of respecting precedent, but from day to day, in how they decide cases, confront issues, interpret statutes and interpret the Constitution.
Judges must also understand that their role is to apply the rules rather than remake the rules according to their own policy views and have the fortitude to stand up to the other political branches in deciding that an action is unconstitutional or otherwise unlawful. In maintain their role in standing up to other political branches and refraining from remaking the law, Judges must have the ability to tune out criticism, so that they are able to stand up for unpopular positions.
In their conduct, Judges must maintain a proper demeanor, keeping emotions in check, be collegial, and have the ability to work with colleagues and learn from them in order to reach the best decisions. And finally in reaching their decisions, Judges must be clear in explaining their reasoning behind a decision.
Of course, for us to be good judges and good umpires, the rule-makers can help by drafting rules that are as clear as possible. And, in the federal system, that means Congress.