Whether you're hosting a small and informal cocktail party or a large and lavish one, probably the biggest challenges are deciding what beverages to serve and how much to have on hand.
One option is to limit your menu by offering only one or two types of mixed drinks, along with wine or Champagne and perhaps beer. Creating a theme for your party can also help you narrow the drink choices. For instance, margaritas and sangria are perfect for a Mexican-themed party.
A good rule of thumb is that the vast majority of guests consume no more than one drink per hour. So if you multiply the number of guests by the number of hours the party is scheduled to last, you'll have an approximate idea of how many drinks you will serve.
When estimating quantities, use the following guidelines:
A 750ml bottle will yield 17 shots of liquor or 5 glasses of wine.
A 1-liter bottle will provide 22 shots, or mixer for about 12 highballs.
5 lb. of medium-size ice cubes will fill about 24 ten-fl.-oz. glasses.
Be sure to offer a selection of nonalcoholic beverages, and serve your guests plenty of food.