To me the most important thing is Use THE RIGHT PEOPLE the president must have the ability to put the right person in the right place at the right time, loyalty should be only a secondary consideration. Bush Jr get a F- on this. The second most important trait is not to stick one's idealogy like it is the holy bible. Things change and different situation require different solutions, one has to be practical. The last key ability is to be able to unit the country to get things done. If a president want to reform healthcare for example, he must get the whole country behind it and not just think of a solution in the vacuum. Any other ideas.
Finding qualified and brilliant people willing to sacrifice for our country isn't as difficult as it seems for a Commander in Chief. In 2000, Bush's cabinet was considered highly experienced and polished who had served under previous admins with various success. As president, I highly doubt there are ever right answers with the right person/counsel. If one is lucky, he may make the right decision at the right time, but he same decision could be wrong a day or month later. Where Bush failed was being trapped under their genius/charisma and wholly committing to their opinions above other reasonable yet conflicting viewpoints. He allowed the intercabinet bickering to remain long after invading Iraq, and Powell's unceremonious exit severely caused a bad situation to grow worse. If Powell kept a relationship to Bush as Rice had, I think the nation would've fared better foreign policy-wise. So as a leader, a great president must manage these egos and find a constructive solution without causing festering tension between the faction whose opinion he will choose against. He can't play favorites, even if there are friends he likes and trust more. This gives him the leeway to admit that he doesn't have to know everything of a situation, but has the trust in the capabilities of his staff to work as a machine and deliver him a reliable assessment to decide upon.