A few years ago, on a flight BUR-SFO, a mother and her son quietly approached me, asking if they could borrow a button down/collared shirt from me to wear to get on the plane. I was surprised, but I quickly understood, and since they were quietly very polite about it, and didn't seem like they were trying to take advantage of the situation as NRSAs, i.e. just trying to get home in coach, I agreed. Must have been because I was one of the few people standing around with a rollaboard, and looked approachable (for various reasons).

I wouldn't give shoes though... ugh. or to an NRSA who had a "bad attitude"... or who was pestering people.

Also, you've seen the freakonomics-type observation that suggests that when people are paid a low amount for something, they are even less willing than if it's for free/charity?