"When the opponent expand, I contract, When he contracts, I expand, And when there is an opportunity, I do not hit--it hits all by itself" - Bruce Lee
This is what I want to be able do do one day, but with control.
How many times have you accidentally hit your training partner? Sometimes, by chance, perhaps. Other times, maybe the forces were actually in the right direction for once, and just because there was no obstacle, your pliable arms, legs, or body just got through. "Ooops, sorry", you say.
But wait! Let's go back to that moment and see what happened. Then it becomes too complicated, because you start to think about what you did, how you placed your arm, where your pressure was, etc... and everything begins to fall apart. Don't get me wrong, I think analysis is a good thing. It just might be difficult to get right back to that instance of an undisturbed mental state of, well, just flowing I guess. Not thinking too hard.
Techniques can certainly teach proper positioning. Which is static though. Valid and good to learn. In application, it is different altogether! We don't fire off neurons and make our arm into bong sau or tan sau. It should one day, one day, be automatic. When bong or tan or whatever sau just occurs on its own - but just as quickly as it came, it should dissipate again into the next "photo-op" position let's say. Maybe it'll be a fak sau, or a punch, or something else we can give a name to. Who knows? But in the end, it should hit all by itself!