Below are a few men's hat customs and their origin compliled by asking an older, hat wearing gentleman. It's up to you to follow them or not.
TIPPING YOUR HAT
Used when meeting a lady or as a way to say thank you, excuse me, hello, goodbye, you’re welcome or how do you do.
This custom comes from the military custom of saluting which is derived from the medieval knights raising their masks as a show of friendliness.
REMOVING YOUR HAT INDOORS
Hats are to be removed indoors except in places akin to public places such as train stations, hallways, elevators (unless women are present) and places of worship, depending on custom.
This custom is derived from military men removing their helmets as a gesture of good intentions.