Demonstrations by the instructor should be performed slowly and deliberately and very accurately without mistakes. They should be a model showing how to do the job correctly. It's important to remember that the instructor demonstrates to show the correct way to do the job and not to show how clever he or she is operating the truck.
During the demonstration the instructor should give a commentary. There seems to be a lot of confusion as to what is meant by a commentary. Many instructors talk far too much at this stage completely forgetting that they have already given a detailed explanation. Remember you cannot have the lesson plan with you when you drive the truck!
In our lesson of turning left into an aisle we would bring out key points such as the position of the truck widthways in the aisle, the turning point, steering on full lock, and so on. These key points should be made either exactly at the same time as they occur or just before they occur. It's no good, for example, turning into the stack and then saying "did you see where I started to turn"? - It's too late!
It is also important that the instructor does not resort to negative tuition, in other words showing the trainees the wrong way to do something. An example might be taking a flying leap off the truck and then saying "don't let me catch you getting off like that". The problem is the trainees now have a picture in their minds of the instructor doing it incorrectly.
After the demonstration, the instructor again should make certain that the trainees know what they are going to be doing when they get on the truck. More questions may be appropriate at this stage to confirm understanding.