As they move through the checklist, they work with an eye to efficiency, remembering, for instance, to check warning lights, fuel gauges, and navigation and landing lights at the same time that they turn on the battery to lower the flaps. They save energy and time by checking all of the electrically powered elements at once. If they have called for fuel, they don't waste time draining the fuel sumps until after the airplane has been refueled.
These flight instructors also pay attention to details, draining the highest fuel sumps first and ending with the lowest drains to avoid pulling any contaminants through the system where they might end up out of reach of the drains. And, when they get to the nose, they move the airplane backwards and forwards so that they can check all of the tread on the tires, not just the parts that are showing. These top candidates even remember to position the main wheels in front of any obstacles, such as tiedown anchors or pavement edges, that would require extra engine power for initial taxi.
And the best flight instructors always operate with safety in mind. They visually inspect the fuel quantity in both tanks even if they have just watched a lineman pump fuel into the airplane. When they check the propeller for cracks and gouges, they position their bodies so that they won't be struck in the unlikely event that the propeller rotates unexpectedly. When they clear the area before startup, they don't just shout "CLEAR!" they actually look to make certain no one is in danger of walking into the spinning propeller. If necessary, before starting the airplane, they position it to avoid sending propwash-propelled debris into hangars or people.
Once they're ready to go and strapped into their seats, the best instructors verbally review the objectives of the flight to confirm that I, and they, understand the plan. They brief me, the "student," about who's in command, proper flight control transfer procedures, and air traffic watch procedures.
On the radio, the best instructors communicate professionally, confining responses to essential information. They don't tie up the frequency with chatter, and they don't step on other pilots' communications.
During taxi and runup, they remember to check not only that the flight controls move, but also that they move in the proper directions. They look to see that the flight instruments respond correctly to the movements of the airplane on the ground. They never taxi too fast, and they always position the flight controls correctly for wind conditions. After the runup, first-rate flight instructors scan every instrument, control, and circuit breaker and review the manufacturer's pretakeoff checklist before calling for takeoff clearance.
When I evaluate a flight instructor who does all of these things, I know exactly what will follow. The flight itself will be smooth and well executed, and this applicant will be my newest flight instructor.