Consider the owner of the plane. If the plane is owned by the student, make sure he completely pre-flights the aircraft. Teach/explain what needs to be checked and why. Do that no matter what. Watch him do it after you show/tell him what needs to be done. Use the show and tell method followed by a 'you do it now' attitude.

If the plane is a club trainer, what I do is gather the students around (we did that for a group of four a short time back) and show them what I do for a pre-flight and a complete system check right down to the range check, to pulling on control surfaces (hinges), checking the servo linkage and servo arm screws (I've seen them loose), throttle settings so that it is not jammed to the ends of either the throttle or the servo stops, and so on.. binding in the linkage, aircraft covering is not flapping around, all that stuff. I show them what I do then make one or two of them do it as soon after I show them. Then, just prior to the student's turn at the buddy box, I make him do a cursory system check to make sure he understands what needs to be looked at and why. I then make sure that all controls work as intended (elevator goes up when the stick is pulled back, the right aileron goes up with right aileron input -- do these checks for both the buddy box and the main transmitter... and so on.

DS

This may take a half hour, but it will be the best half hour spent on that plane and with the student. It develops good habits and a routine that will save aircraft.