Know the Rules
Traditional etiquette sets down very strict rules for which beverages should be consumed from which glasses. It is important to develop a working knowledge of these rules so that any breaches of traditional etiquette are intentional rather than accidental. Entire books and websites are dedicated to the topic, but the basics are fairly easy to understand.
The largest tulip-shaped glasses are for red wines, as they allow the wine to breathe. Smaller tulip-shaped glasses help preserve the temperature of white wine, which is traditionally served chilled. Tall, thin flutes are for Champagne and sparkling wines, while small, rounded dessert glasses are for sweet wines. Port is served in dedicated narrow port glasses. Small sherry glasses were designed for serving sherry, but are also appropriate for liqueurs and other aperitifs.
Beer glasses come in all shapes and sizes, from hypnotic curved designs to elaborate German steins. Although some beer drinkers swear by elaborate systems of matching the beer to a specific type of glass, these customs are not enshrined in traditional etiquette, so you will not be breaking any rules if you serve all beers in the same type of glass. If you want to separate the beer glasses, a loose rule of thumb is to serve lagers in Pilsner glasses and everything else in pints.
Of course, many liquors also have their own traditional glassware, from brandy snifters to highball glasses. However, you will not go wrong at your special event if you provide an assortment of sizes including shot glasses, rather than trying to determine the exact glass for each potential cocktail that your guests might desire.
Non-alcoholic beverages can be served in standard glassware such as tumblers for cold beverages and mugs for coffee and tea. If you want to include a timed coffee or tea service, you might choose to provide demitasse cups and other specifically matched glassware.
Think About Place Settings
If you are serving a formal plated dinner, you might want to follow traditional formal etiquette rules for place settings. A traditional place setting includes a water goblet and up to four wine glasses—typically red wine, white wine, a champagne flute, and a sherry glass. Beer, liquor, and non-alcoholic beverage glasses are not part of a traditional place setting, although these drinks may be brought to the table by each guest, or by a server upon request.
Consider Your Theme
Knowing the traditional rules means you can break them appropriately. If your event is casual, carefree, and fun, feel free to break out the bright colours and whimsical patterns. If you have a definite colour scheme in mind, look for glassware in one or more of your chosen colours. Large margarita glasses, casual mason jars, and flowered wine glasses all have their place at certain events. Let your theme guide your decisions.
Match the Formality
Very formal events require you to pay strict attention to etiquette, but formal glassware looks out of place at a more casual gathering. If the guest of honour is in a ball gown or white tie, err on the side of formality. If the dress code is jeans or beachwear, choose more casual glassware.
Also consider your venue, the ages of your guests, and the activities you have planned. Fragile stemware is not the best choice for a backyard party with dozens of toddlers in attendance. Heavy glasses could be difficult for very elderly attendees to manage. Buffet-style meals require guests to balance their glasses along with their plates. Outdoor locations with uneven ground make it more likely for guests to trip and drop things.
Trust Your Instincts
Ultimately, there is no single best choice in glassware for all events. Your party is a reflection of your tastes and personal style, so you are the best judge of what you want to use. Consider all of the relevant factors, speak with your party professional, and then trust your instincts to guide you to the right decision.