O.K. I will try and describe how I teach correct height judgement for the flare and height judgement after the flare.
First the flare:
I use a definable point on the runway as the flare point, usually the first big hash marks and runway numbers. This is the aim point on final, during the last fifty feet in a small airplane the aim point will start to grow in size and also appear to spread out in your vision, at about twenty feet the picture will become quite clear that you are about to fly into the runway. It is at this point that I start the flare with most light aircraft.
Rather than describe to the student what I am seeing I count down the height from fifty feet to the flare and have them memorize what they observe up to and at the flare point, this avoids any misunderstanding of what I am trying to describe. By using this method the student will quickly imprint the picture that she / he is seeing.
Once the flare is started you then look straight ahead down the runway to the point where apparent movement of the runway markers stop.
What is................... " Apparent movement of the runway " ..........
There is a point ahead of the airplane where apparent movement of the runway towards you ceases. This point will change with the speed of the airplane and eye height above the runway.
For light aircraft that approach in the 50 to 70 knot speed envelope the apparent movement of the runway,,, runway marks, will be approximately five hundred feet ahead of the airplane.
That is the distance ahead of the airplane that your centre of sight should be aimed at. This will give you the proper picture that will allow you to best judge height.
The reason that this works is you can "see" the runway get closer in your peripheral vision as the runway movement close to the airplane changes. Also you can "see" the far end of the runway in the top of your peripheral vision, this is your attitude guide that allows you to change the attitude as speed and lift decays.
Ideally the airplane should contact the runway in the attitude that the stall occurs. ( Except wheel landings in taildraggers. )
If the nose blocks out your view ahead as you increase the nose up attitude during the hold off all you need do is move your head and sight line to the side and look along the side of the nose at the runway still using the same distance ahead that gives the picture that you need. Where apparent movement stops.
Note as you slow down the runway movement picture moves progressively closer. ( About three to five hundred feet ahead is just about right at touch down.
I have an excellent movie that was taken at Airbus Industries during my A320 training and I use it when describing what to look for when determining where the apparent runway movement stops. The beauty of the movie is I can stop it and show the point on the runway where this occurs, then start it up again.
Also the movie is perfect for the flare picture, the A320 approaches at a higher speed than a light aircraft but the picture remains the same when looking at the flare point, it just happens faster. ( oh by the way you don't actually flare an A320 like you do a Bug Smasher but the height judgement is the same. ( aided by the computer voice giving you exact height.
I am willing to keep answering any and all questions about how I teach height and speed judgement, all I wish to do is make flying safer and easier for those who fly for the love of it.
My system works because I have been perfecting it for fifty years and I used to teach crop dusting where if you do not know how to accurately judge height and speed you die.
So if you all want me to keep explaining my method I am willing to type until everyone understands how I do it.
By the way:::
I use a camcorder for all my advanced flight training, when the student fu..s up it is easy to review it right after the flight and explain where it started to go wrong and how to prevent repeating the fu.. up