Many years ago I wanted to define a "good" captain. I found it quite difficult until I came up with a brainwave - lets identify a "bad" captain! Always turns up to work late shabbily turned out and unprepared, is offhand to fellow crewmembers, doesn't follow Sops etc.
Now just invert the "bad" captain picture and what do you get? Always arrives at work on time (or even early!), well turned out and well prepared , is pleasant to fellow crew members, follows Sops etc - you get the idea I am sure!
That said there are, as they say, many different ways of skinning a cat! I also think a good captain has some "style" ! Some of the best ones I have ever flown with have had a unique style whilst still following the Sops etc. They have been fun to fly with but they also really knew the job inside out.