I would dress up and pretend to be a famous rich person for the time I'm there. Sometimes it so fun, and feels so silly to do it, but its awesome
Whenever I'm in LA, we go to Chateau Marmont, a popular hotel/ restaurant for celebrities. You go, eat an expensive breakfast/ appetizer for an hour, and pretend to be famous while people coyly look around the room to see if they know you from somewhere.
I would dress how I normally dress and I would only want to impress someone if they had something to offer me, not random people...and especially not the hotel staff (and ESPECIALLY not those prickish valet dudes that think they are one step away from Wall Street).