How do you practice the 'shadowless' kick in your wing chun forms?

[Paddington]

(Some of you are going to be aware of this already and although I welcome your training tips, for some this will be 'new' and unconsidered. What follows is an account of my training experiences from a few years back and although I have mentioned it in passing before, some new to these forums may find it useful to be repeated and explained more fully)

One day I attended a private lesson with my previous Sifu and we focused on chum kui and section two in particular.

In the Ip Man lineage (and others), section two opens by turning to the left with a lan sau, followed by a front kick. Some refer to this kick as dung toi or hay gerk (lifting kick), where as others may practice a different kick that is more thrusting in nature and is commonly referred to as jic gerk or jic tek. I have even seen some practice a side kick.

For myself I sometimes alternate between practicing dung toi and jic gerk, depending upon what particular aspect I am training that day and although a discussion of the relative merits of each kick is indeed interesting, it was more the role of the lan sau that I brought up for discussion in my session with my previous Sifu.

I explained to him that increasingly I was beginning to view the forms, that lan sau in section two in particular, not within the context of direct applications but rather in the context of training a skill; the skill in question here was wing chun's 'shadowless kick'.

By shadowless kick most, and I could be mistaken, are referring to the ability to not telegraph the kick so that the opponent has no visual reference that it is on its way.

I put it to my previous Sifu that the lan sau, when you look at it when performing the kick, is like a reference rod or stick emanating from the centre of a circle so that when a small movement occurs at the centre, that movement is larger and more noticeable further along the 'rod'. You can notice similar exaggerations and amplifications in movement when practicing the pole form.

I explained that when my lan sau moves it is because I am exhibiting bad form in my kick; my body may bend forward at the waste, indicated by the lan sau dropping or I may raise in my stance or lean backwards, indicated by my lan sau rising.

By focusing on keeping the lan sau still, I suggested, I found that I could better develop the ability to not telegraph my front kicks, rendering them 'shadowless' if you will. To my mind back when wing chun was beginning to form as a distinct martial arts style, there was little opportunity to practice in front of a mirror within the cosy confines of a custom kwoon. So, I suggested, it made sense to use the lan sau this way if you wanted to practice not telegraphing your kicks.

My previous Sifu did me the honour of listening to what I had to say and turned away from me and preceded to walk to the opposite side of the kwoon, to practice the lan sau and kick as I described. After a few repetitions he came back and said to me "thanks for that".

It could just be the case that he was being nice to me and that this way to train the beginning of section two was commonly known but either way, I thought I would relay my experiences to you in the hope that perhaps some of you may find a positive use for them.

My question to those more experienced and skilled than I is, how do you practice the 'shadowless kick' in your forms? Also, how do you practice it outside of your forms?

EDIT: I would add that this is not the only way to train the beginning movements of chum kui and as I have said, it all depends on what I want to develop in a particular training session.