In an interview with American Cinematographer originally published five years ago:

I probably look for the same qualities everyone else looks for when they hire people. I generally look for someone who’s both pleasant and technically astute. For example, if I’m hiring a camera operator, he has to be able to fulfill his primary function, but I also want that person to be able to help the assistant get everything put together properly, anticipate any problems that might arise, and so on. I don’t want a situation where he’s operating one moment and making phone calls the next. The operator has to be intelligent and able to relate well to actors. I feel most comfortable with someone who’s smart, specific and easy to deal with. It’s the same with the assistant cameraman — who, I think, has one of the most difficult jobs on the set.

Being technically competent is an obvious prerequisite for the camera department and everyone wants to work with someone who’s smart, but being “pleasant” and “easy to deal with” are two underrated qualities that make those above-the-line more likely to hire you for the next job.

The rest of the interview is well-worth reading for more of the late cinematographer’s pragmatic wisdom and sarcastic cynicism: “…that’s the nature of the business: It’s okay to approve an extra 20 feet for the star’s trailer, but if you need one more grip for a day, you can forget it!”