There are certain ‘old school’ habits that I prefer to mere blind adherence to the bare minimum that may or may not be listed in check lists or the AFM. First fllight of day checking trims through full range serves two useful purposes. 1. it ensures cables, pulleys, actuater rods and tabs are not binding and 2. reinforces pilot ‘muscle memory’ so that the lesser used of those controls can be found without looking. Only this week I caught a partially seized trim circuit in an old aircraft and which is still under investigation. Also the crossfeed function is worth checking on every aircraft type, yet often this won’t be called up except as a maintenance check. The maintenance check itself may only occur at six or twelve month intervals. Use it or lose it.
But another old school habit needs to be to not accept any interruption to your workflow or whatever habit pattern you use to prepare for flight. Today that includes ignoring your mobile phone. Some people have a real problem with that.
Not saying this is what happened here, but it does seem from reports of doors and lockers left open that the pilot lacked organisational discipline.