How do you NOT forget the last diskette
Many years ago we had a test tool called TRAPS - Test Recording and Playback System. It actually showed a picture of a tape moving at the bottom of the screen with the commands being executed. It was possible to insert and delete commands in the tape.
However, the problem lay with installation. The product came on 6 diskettes and had to be installed on each machine separately using the correct diskettes for the operating system. Suffice to say it was frustrating to do this repeatedly and take the time to do each machine. Inevitably the last diskette was forgotten in the last machine while we moved to the next machine. That required a trip back and two machines being out of commission while we completed items.
Eventually (very eventually) we remembered to count the diskettes prior to departure from each machine. It sounds trivial but it saved a lot of effort.