Travel rules are not written in stone—some of what people used to consider absolute no-nos have changed over the years. Acceptable biases have evolved as people worldwide have become more open to travel to many different parts of the globe.
For some reason, using Instagram to research your next vacation went out of fashion, and travelers reacted badly to the idea. It is unknown why the idea of checking out travel Instagrams with great photos became unfashionable.
Another controversial travel belief is that the cities of Paris and Milan are great. Too many people look down on these great cities, and we are still determining why they do. Maybe it is their popularity?
An exciting recommendation that travel mavens would look down upon was getting on one of those hop-on/hop-off tour buses. After you arrive and if you are jet lagged, drop off your luggage in the room and take a bus to relax and see the city.