I think there's different tiers and types of posh.
There's the aspiring posh people who are concerned with how they appear to neighbours, friends etc. Neutral accents, they have their neat gardens, nice decor, clean cars, the John Lewis shoppers who complains about standards slipping, Smeg/Dualit appliances, Joules, Boden coordinated type clothing etc - nothing too loud or garish. Meals out etc.
Then there's the aristocracy. Probably a bit eccentric but doesn't care. Uncoordinated clothing, clash of colours - tweed check jackets and lemon surprise trousers; scruffy undyed hair, worn, antique furniture, countryside orientated with farming/hunting, public school background, networkers, concerned about money cos of grade listed building repairs, sweary, drinks alot but doesn't care, lots of gun dogs and a few cats, not too bothered about cleanliness. Live in staff.