I want to add another item to the list:
Inadequate, poor or simply non existent flight planning and preparation.
I remember my first map reading exercise. The cockpit was a complete mess of nav charts, weight and balance sheets, performance graphs, weather printouts, NOTAMs and my flight plan (buried in there somewhere) when we took off. No sooner were we wheels up when my instructor asked me for my pencil because he wanted to change a waypoint on the route I had chosen. A mere nanosecond into the proceeding chaos I learned a very important lesson about proper preparation.
