Technique: Principle vs Preference

Over the last few months of teaching both classes and one on one sessions i have found myself saying one thing a lot. I have been showing my students how to break down the techniques i have been teaching into principles and preferences.
This has become something of a habit due to the frequency that phrases like "but Joe Bloggs does it this way" or "Joe Bloggs told me to use this grip" are used by students when a technique is taught. I recall as a white belt that i got information from a lot of sources (youtube started towards the end of this time) and i often asked those same questions. Looking back i wish i had just practiced what i was taught because i would probably have learnt more and wouldn't have wasted my coaches time. However, i didn't and now it is my turn to answer the same questions.
What i have learned, though is that every technique has a core principle that is universal regardless of who is doing it (in fact i would go so far as to say if the principle differs between two versions of a technique then you are dealing with 2 distinct, albeit similar, techniques), but that personal preferences can allow for variations in how it is applied.
A great example of this can be seen in the side control escape to guard. It is one of the first techniques that most of us learn and is taught with a lot of variation from coach to coach. As an example just a few versions of the job of the outside arm in this escape are as follows:

1. It reaches across your body towards your hip so that it can form a frame on your opponents hip or establish an underhook.

Jeremy Arel of greatgrappling.com

2. The forearm braces under the jaw of your opponent to create a frame for your escape.

Kurt Osiander of Ralph Gracie Jiu Jitsu

3. You use your arm to reach across your opponents head in order to interfere with their posture.

Henry Akins of Dynamix Martial Arts

Like i said that was just three variants on just one limb, there are many more i can think of and they all have merit depending on the circumstances. However none of these are the core principles of the technique. The core principles that are constant in all the successful variants of this escape are:

1. Creating space through a bridging movement.
2. Maintaining that space by creating some sort of frame or posture.
3. Hip escaping away from your opponent and inserting a knee.
4. Straightening up and establishing a guard.

All successful versions of this technique contain these principles despite having almost infinite variations of the "preferences".
When i teach now i try to explain to my students what part is a fundamental principle and what is a variation, for 2 reasons. The first is to help them realise that even if it isn't identical to the one that they originally learnt it isn't "wrong" and the second is to let them know that they are still getting benefit from training the technique even if they don't consider it to suit "their game" at that stage.
My philosophy now is to try anything that is taught to me, not second guess it straight away. I just wish someone had of explained the difference between principle and preference to me sooner so that i wouldn't have taken so many years to get the philosophy right.
Have fun on the mat.