The flavors of cocktails and mixed drinks come from many ingredients, some used only rarely or in small quantities. But omitting them from a recipe that requires them is a prescription for an inferior drinking experience. Below is a list of the basic mixers and modifiers you'll need, along with extras for occasional use.

Mixers

Essentials:
Bottled still mineral water
Club soda or seltzer
Cola
Cranberry juice cocktail
Fresh lemon juice
Fresh lime juice
Fresh orange juice
Ginger ale
Grapefruit juice
Lemon-lime soda
Pineapple juice
Tomato juice
Tonic water

Extras:
Beef bouillon
Ginger beer (spicier than ginger ale)
Heavy cream
Light cream
Milk

Modifiers

Essentials:
Angostura or other bitters
Cream of Coconut
Grenadine
Simple syrup
Sweet-and-sour mix
Sweetened lime juice (such as Rose's)

Extras:
Eggs
Falernum syrup
Orange bitters
Orange flower water
Orgeat syrup
Peychaud bitters
Rose water

Adapted fromWilliams-Sonoma Guides: The Bar Guide by Ray Foley, 0-7370-0062-7, (Time-Life Books, 1999)