movies and music from the mid 30's to early 60's, (all before I was born), when I think of class/classy, timeless traits are what first come to mind.
How a Gentleman treats a Lady:
Does he seat her first at the restaurant table?
Does he rise to great her when she comes in the room?
Does he position himself closer to the street when they are out walking?
Does he send a hand-written note when practical?
Does he focus on her fully when she is sharing about her day/experience, and ask follow-up questions to show real interest?
How a Lady treats a Gentleman:
Does she allow him to be chivalrous?
Does she give him time to really answer her questions, or after a two-second pause she continues on?
Is she confident in being feminine?
For both:
Do they treat others, even if the waiter, cashier, taxi driver, etc. with dignity and respect? Or ignore/look down upon those with less money? (The latter probably being the quickest way I will decide to never see someone again.)
Do they put away the phones at meal time and focus on each other?
I think truly classy people attract others to them not because they themselves are some 'gleaming star', but because people find them genuine and accepting, and comfortable to be around. Truly classy people, in my opinion, appeal to people's higher aspirations.
Classy for me has never been about checking to see if the soles of her shoes were red, or what name is on the tag of her lingerie. I know ladies who are just as classy at a picnic in blouse and shorts and sandals, as they are in an evening gown ballroom dancing with me