Closing pictures are guesses; last frames are facts. Draw the next shot only after the previous one is filmed, from its last frame; if you refilm a shot, take its last frame again for the shot after it. Thrown to another person: end shot A on the throw, open shot B on the catcher already looking at the incoming ball - never show the flight twice. A hand-off stays inside one shot. If the object is meant to stay behind, say so, or the model brings it along.
-The video model reads clock time. Its own guide writes cut points as At 00:03.500 and pins pictures to second marks. We measured it: "in the frame for about four seconds" was obeyed to the second - and the two seconds left over got an exit the picture did not offer, so the car stopped. Used well, time is the most precise direction there is.
The shot's length is the whole budget. Set the length first (Estimate on the storyboard), then write the beats to it, in order, and give a second only where a beat must land:
++The red Mustang, Dorothy driving and Toto upright on the front passenger seat, comes along the gravel drive from the right at speed. At 00:03 she draws level with the tractor: her right hand presses the centre of the wheel and the horn sounds twice, exactly as her hand presses, then lifts in a quick wave toward Henry. Toto barks twice at him. The car keeps going up the drive, turns right where it bends toward the house, and by 00:07 has rolled to a stop in front of the porch, its dust catching up. Henry straightens in the dust by the tractor and looks after the car.
at 00:03 is a moment, by 00:07 a deadline. Marks increase; the last one sits inside the shot with about a second to spare. No more than three in a shot - five is two shots.