In Turkey, the sweet, thick black coffee they brew is poured straight from the brass coffee pot in which it's brewed into small cups of beaten brass. Italians favor elegant little china cups and saucers for their espresso, but often drink it standing up when they stop into the neighborhood espresso bar. Stop by a French café for a morning café au lait and the strong black coffee and hot milk will be poured into a coffee cup as large as a breakfast cereal bowl.
A Brazilian coffee drinker will drink many cups of café come leite daily from porcelain cups and saucers presented on a metal tray, accompanied by a silver bowl mounded with lumps of white or light brown sugar. No habitué of an all-American diner would expect anything less than hot coffee in a sturdy mug. Get that same coffee to go in New York City, and you'd be surprised if it didn't come in a paper cup decorated with blue-and-white Greek-inspired motifs.
In other words, there is no one proper way for serving coffee or enjoying it. The only reigning rule in proper coffee etiquette is to be sure to offer it to your guests, whether you're welcoming them in a restaurant or café, in your office, or in your home. That said, there are some basic rules you can follow
Offer only the best quality coffee you can make, freshly brewed from freshly roasted coffee beans that you grind fresh just before brewing. (See Grinding Coffee and Brewing Coffee.)
Bearing in mind that some people drink only decaffeinated coffee, have a supply of decaffeinated whole bean coffee on hand for those who want it. If you yourself brew flavored coffee beans, keep a supply of regular unflavored whole bean coffee on hand for guests who prefer it.
Present the coffee in appropriate containers: elegant cups and saucers for a special dinner party, for example, or playfully decorated mugs for a casual gathering of friends.
Before serving just a few guests, ask if any take milk or cream and sugar; for a larger gathering, prepare these in one or more small pitchers or creamers and sugar bowls. Have separate pitchers of low-fat or nonfat milk and a separate bowl holding packets of artificial sweetener on hand for guests who might prefer them.
Just as wine comes alive most fully when it accompanies food, so does good coffee benefit from the companionship of something to nibble. Put out platters or bowls of coffee accompaniments appropriate to the time of day or occasion, from a few simple cookies to a home-baked coffee cake to elegant hand-dipped chocolate truffles.
It's always a good idea to brew enough coffee to offer your guests refills. Have a thermos carafe on hand to keep the extra coffee hot, fresh, and ready to refill anyone's cup.