Personaly I think the biggest fault when learning is to not understand, or have it explained, how important it is to use CBM into a turn. Without it you will turn like a block of wood. Give it a try. Think Reverse Turn Foxtrot. From a CBMP position as in the Feather Step.Step foreward LF. with the right shoulder leading, now turn. Then try without. Does anyone have a better way of explaining this, or any comments that may help others. Can we dance without CBM. Yes we can, but like a block of wood.

When complete beginners start to learn to dance, they have so many things to worry about and absorb that it's probably better to wait until at least the basic steps and timing are in place, then introduce more subtle concepts, of which there are many (not just cbm).
One way i've used to try to explain cbm and allow people to do it naturally is to ask them to do the natural turn in slow waltz, on their own, with their arms extended out at the sides. But to do it so that the turning action is continuous. It's impossible to make the turning continuous without using cbm. (it's easy to demonstrate 'with' and 'without' cbm). this makes it easy for learners to do it, and also explains why it's needed.
That said, many social dancers have a great time and if you mentioned CBM to them they would assume you were talking about misslies

Phil. I like the missile comment. Somebody I know dances that way. just don't get in his path. But back to the subject. I agree that with a beginner it might be off putting to insist on CBM
But in the very beginning in the Waltz with just change steps down the floor. I could see our teacher doing a slight CBM on his first step which he drew our attention to. Which i always tried to copy. He just for the record was fourth in the world at that time.

Dear Phil,

Is there any change in reverse turn following feather step now?

Two weeks ago, my teacher said , I can simply position my RF diag. back under the same condition of second quick of previous feather step , then pull the left heel closed to the RF , heel turn...So, I transfer my body weight diaganlly across the floor without recover, without CBM. It seems smooth also.
I don't know is it a new technique or to make a fool of me.

There was a mild conflict earlier when we danced foxtrot . My teacher said , the foot work is: RF HT, LF HT , RF TH /LF HT RF HT LF TH alternately.
In my mind , the wave we called contents of feather step and three step . In feather step , the foot work is RF HT, LF T, RF TH.
He said, who told you wave composed of feather step and three step ?! You should do HT or call off this step forever if you persisted LF T.
I answered :I would not want to do wrong even you threated me like that . it is T, not HT in spite of HT easier in transfering body weight.( similar thing occurred in open reverse turn from PP in waltz. He showed HT ( lady, step 2 RF ) not T.), and logically , when the first step is HT, the next step should be T or TH. the three stpeps is special...

Yichin 1. Your troubles are over if as man or lady after CBM on the first quick you now go into CBMP on the second quick. The Wave. You can enter the Wave from a Reverse turn and Feather Finish. You can also enter the Wave from a Natural position. They are not the same . The Natural will have a back Feather followed by a Three step. The Reverse has a Three Step before the Feather. These are from the man's position. Ladies the natural opposite. I can't make any sense out of my book which is very old. I don't think they used to go all the way around the short side of the hall in a Wave in those days. The one mentioned is called the Reverse Wave it doesn't say anything about starting from a Natural Turn. I think your coach wants you to do the Reverse Wave.