Your performance depends on your people. Select the best, train them and back them. When errors occur, give sharper guidance. If errors persist or if the fit feels wrong, help them move on. The country cannot afford amateur hour in the White House.
There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know.
Treat each federal dollar as if it was hard earned; it was - by a taxpayer.
One of your tasks is to separate the 'personal' from the 'substantive.' The two can become confused, especially if someone rubs the President wrong.
Be able to resign. It will improve your value to the President and do wonders for your performance.
Public servants are paid to serve the American people. Do it well.
