'Don't too casual'

Again, a lovely direct to English translation. Sifu has only started saying this again (I don't remember him mentioning it since I started in Jan 2014) and it has been something that really helped me.

One of the biggest differences with learning this martial art as opposed to others is that each movement has to be relaxed and controlled with the 'little idea' or more importantly, not controlled by your big idea.

With this style Sifu tells you to relax but don't 'think' relaxed because that involves using your big idea. So if you are trying to 'casually' move your hand so as to not tense it, you are probably using your 'big idea.'

This could be better demonstrated than when Sifu approaches us when we're standing to test us with various movements. He implores us to not be too casual when moving our arm from hanging by our side to which ever position he is testing. 

Each and every movement needs to be controlled with the little idea and not using the big idea. Casually moving your arm is evidence of you using the big idea when trying not to think too hard.
DONT. TOO. CASUAL...