The ability create a team identity within a short space of time
The ability to get the best out of players beyond the 6 or 7 main guys
The ability to make in game adjustments on the fly in high pressure situations
Knowing how to get the best out of your number one option. Identifying what the main man needs to be surrounded by to neutralize his weaknesses and support his strengths
Hard to get all of these qualities in one coach. I would say Phil Jackson, Greg Popovich, Larry Bird, Steve Kerr, Stan Van Gundy, Rick Carlisle, Tyron Lue are the coaches I think have embodied at least two of these qualities or more at the highest level at one point or another.
The most important job in basketball in my opinion is general manager and the front office. Identifying talent throught drafts, free agency and trades is very challenging especially in this era where it's nearly impossible to stack stars in their prime on one team.