I am only talking about the last 500 feet. And only for students or people having trouble with landing approaches.
I consider the most important parameter to be glide path control. Speed can vary a little. Later on, speed becomes more important but initially I tell my students that so long as they are plus 10 and minus 5 let it go. I also tell them that there is a minimum speed that they are not to go below at any time until over the fence.
The first part is getting them to understand what the glide path is and how to determine it. Then how to fly it.
If the airplane is above the glide path, put it back on. The easiest and fastest and most accurate way to do that is by using the elevator. If the diversion was small, the speed should not be much affected and will settle down once the glide path is re-established. No need to touch the throttle unless the average speed is not within the parameter established.
Keep the sight picture using elevator and the speed stays the same.
Later, I expect coordinated use of both controls but intially students find it difficult to do this and also intially they do not have the discipline to even be aware that they are off the glide path and do not appreciate how important it is to land at a nominated point on the runway. Good habits should be learned early. Landing accurately is an essential skill.
It is like parking your Toyota in the garage; you simply MUST do it right or you will hit the side or back walls. Landings should have the same discipline and this should be inculcated right from the beginning. I remember doing this in the Air Force and we were not allowed any variance from the standards. I believe it made me a better pilot.
All that you guys have given me is great stuff and reassures me that I am not so far off the well-trodden path.