Yeh shortstripper it ain't black magic.
I use a very simple method to teach height judgement skills to pilots.
First explain it on the ground
Second I fly the airplane and verbally tell the student what I am looking at and have them look at the same area....and also make sure they are printing the picture in their minds.
Then I have them repeat what I just showed them.
I use a video camera to record these lessons and the video is our debreifing tool...if they have fu.ked up an approach , flare or touch down I stop the video and ask them where they were looking and what they thought they saw...
Works every time and all my students can judge their approaches and are sure of their height above the runway.
Chuck E.