Photo: Galateo: The Rules of Polite Behavior, by Florentine Giovanni Della Casa (1503-56) published in Venice in 1558
For example, if you have employees, cleaning ladies, baby sitters...anyone working for you, remember that just because you are paying them, you are not allowed to be rude to them: always show respect and ask things with kindness. If you are considered a rude arrogant person it doesn't matter what you wear or what you own...you will never be seen as an elegant person.
Even at a restaurant be polite to your waiter: he/she is a person like you, that is doing a job and he/she is not getting paid enough money for running around with plates, food and listening to complaints and so on...be polite to that person and do leave at least the right amount of tips.
I could go on and on with examples of good manners, like the ones we have lost: opening a door for a woman if you are a man, giving up your seat in a bus for people that can't stand, returning a favor to show appreciation...
Do you know why the British series "Downton Abbey is so successful even abroad? It has been studied that it's not just the story told, it's the great manners shown by the characters, along with the beautiful clothes and elegant life of the 20s.
Photo: Downton Abbey, photo by the DailyMail
They way you talk is also essential: if you look elegant, but when you open your mouth, you sound like a paysant or worse you use bad words, your exterior elegance immediately disappears in the eyes of others.
So, watch your attitude, your language and what else? Your culture is the third essential thing that makes other people judge you as elegant. I'm not saying you absolutely need a PhD, but you surely need to read books, keep yourself informed, so that when you have a conversation with someone you can understand and tell your opinion.
Ignorance and elegance can't go together. Look at some famous people: there are so many out there that wear expensive clothes and yet when they talk you surely don't judge them as elegant people.
Arrogance, bad attitude, rudeness, ignorance are very much hated, so make sure to keep these negative character traits away from your life, or your children's life: teach them to be elegant since an early age and do give them a good education.
Don't forget that ignorant minds can easily be brainwashed and used and they will never achieve anything good in life.
Do you know why some parents send their kids to French schools? It's not just because French language is elegant of course: it's for the kind of education they receive there. France gave us some of the biggest philosophers, painters, writers, poets in history and if you studied Descartes, Renoir, Voltaire, Baudelaire (just to give you a few big names), your mind will open up, you'll gain relevant and essential culture. I'm sure that by now, you did understand the fundamental rule of pure elegance: elegance comes from within first and then it shows on the outside.
Maybe you will also be able to see why most of these French or Italian girls look elegant whatever they wear: elegance it's actually in their attitude, brain and manners mainly, not only in what they wear and how they wear it.