New Year’s Eve is celebrated in the US like in most of the world with parties, champagne or other type of booze and – at least in New York – with a ball dropping and a loud count down.
In most of the US New Year’s Eve is the only day in the year when grown ups (those willing) are able to dress up and attend costume parties. mardi gras is only celebrated in the New Orleans area and Halloween really is a kid’s event (although people like me use it to dress up at least a little and some grown ups actually have parties) – that leave New Year’s Eve for some foolishness.
people either attend parties with their friends, families, neighbors or go out to official events hosted in hotels, or watch special show in one of the theaters.
Once the big moment of midnight has arrived people wish each other “A Happy New Year” – and depending on how well they know each other or how drunk they are a hug and or kiss are okay
If you send cards you can choose from a variety of expressions in connection with New Year: happy, healthy, successful, prosperous, 0r any combination thereof are standard as well as rather formal expressions for business acquaintances such as “May the New Year bring you much joy and happiness” or “A year of happiness and success”
I that spirit: A happy, healthy and prosperous New Year!