As a Pax I fully agree with SkySista, but I would like to add that in my mind it boils down to one thing:
A great f/a makes a pax feel like individual person and not just a "bum on a seat". While you rightly say:
Make people feel special even by "little things"
That can be as simple as addressing the person directly and not trotting out the same corporate approved words when handing over a cup of coffee.
Sorry to one airlines' crew here (no names, no pack-drill), but a game we play on trans-Atlantic flights is to see who can get the most responses of "You're Welcome" by saying "Thank You" every time you hand something over. If you held eye-contact and said "Sure" or something instead, it would be much more friendly.
The irony here is that for flight attendants, just like a lot of other jobs, the people who do the best job for their company (and ultimately promote the company best) are the ones who do not fit the company mould.