At our club, the instructors wear black trousers and white shirts, ties optional. As far as I can see, trainee instructors and CPL students on the day of their flight test wear the same. It's civvies for the students. I don't think I'd feel right wearing what amounts to an instructor's uniform. Jeans and a t-shirt is my usual attire at weekends and I don't change for flying. Suit trousers and shirt if I come from work.
As for Newcastle Brown Ale... we have a love hate relationship. I love it, it hates me. Pity really.
Carlito