In my home state there are 15 hours of required training. Most of that is in the classroom.
My first CCW class was held by a guy in his home. He carried a large .44 revolver IWB, empty while he instructed. During the classroom time he took the gun out and put it back in the holster several times to demonstrate various things. Each and every time, he opened the cylinder and checked it as soon as it came out of the holster.
He did this not only as his own habit, but to stress the importance of verification EACH and EVERY time he took it out. We were not to assume that since there was no way he had loaded it in front of us without our noticing, that it would still be unloaded the next time he took it out.
It was a very, very good teaching method.