Socializing
Rich people are assumed to be able to comfortably venture outside their comfort zone in social situations and sit next to new people. So if e.g. a son is riding in a car with his new girlfriend, his dad and the girlfriend will sit together in the front seat for example, and the son and his mom in the back
Home Decoration
The arrangement of your home speaks volumes about your pedigree. The rich have:
A medium-sized TV set (the larger the TV, the lower the class!)
Curtains instead of blinds
Old oriental rugs (which hints that they've been in the family for many generations!)
Magazines such as the New Yorker, Town and Country
Clothes
Putting too much effort in your appearance, following the latest fashion trends, striving to be impeccably groomed etc. is a sign of middle class
Habitus
The rich are usually thin
Facial expressions
The rich smile less and less widely than the middle class
Pronunciation
To sound rich pronounce all the syllables in every word
Vocabulary
The rich speak literally and are not pompous. For example, they:
Say “car”, not “limousine”
Say “drinks”, not “cocktails”
Say that someone “died”, not “passed”
Say that someone is “pregnant”, not “expecting”,
Say "people", not "individuals"
Say "job", not "position"
Say "although", not "albeit"
Say "buy", not "purchase"
Say "rich", not "affluent"
Say "start", not "commence"
Say "now", not "currently"
Say "big", not "massive"
Say "meet", not "meet with" or "meet up with"
Say "go", not "proceed"
Say "end", not "terminate"
Say "use", not "utilize"
Finally, when asked “how do you do”, reply “how do you do” and not "fine, thank you"
Foreign Languages