Train for stupidity
We started with thorough training for mechanical failures. Later we added drills for incapacitation and windshear events.
But when something happens outside the curriculum (dropped checklist items are generally not covered, but bite hard), the crew may not catch on in time or improvise without success. I've witnessed glider writeoffs and a fatality where improvisation failed when the crew was faced with a situation outside the curriculum.
For one example, improperly latched side opening canopies are easily handled with a bit of rudder, but all too often pilots screw up and kill themselves or the tow pilot, or write off the glider. Common in these cases is the impulse to save a $6,000 canopy. Gliders with rear opening canopies do much better because a mislatched canopy is immediately lost and the pilot keeps his attention on flying the glider.
There are many more ways to screw up in a transport aircraft and it might help to train how to recognize and manage dropped checklist items or mishandled controls.
Errare humanum est.