I was taught to wear non-nylon clothes and shoes you could walk home in, having initially learnt on Microlights in the unreliable 2 stroke days.
I usually wear outdoors clothing such as Rohan, Craghopper or Columbia.
I reminded a helicopter Instructor of this when we had a total electrical failure in an R44 and had to walk through the countryside and eventually get the train home. I was dressed on this sweltering hot day in my usual outdoors wear of Craghopper trousers and Columbia shirt and he in shorts, t-shirt and flipflops.
He looked cool in the Heli but a bit of a prat (and cold) waiting at the station.