Standard ingredients for basic eggnog are eggs, sugar, whole milk, heavy cream and nutmeg. Salt and vanilla extract are other possible ingredients. Types of alcohol for eggnog typically include bourbon, dark rum and cognac.
To make a basic eggnog recipe from FoodNetwork.com, beat 4 egg yolks in a stand mixer until they're frothy. Add 1/3 cup sugar, beating the yolks until the sugar dissolves. Add 1 pint whole milk, 1 cup heavy cream and grated nutmeg, then mix in 3 of ounces bourbon.
Separately, beat 4 egg whites until soft peaks form. With the mixer running, gradually add 1 tablespoon sugar, and continue beating the whites until stiff peaks form. Blend this with the egg yolk mixture.
A cooked eggnog recipe from About.com calls for whisking together 6 eggs, 2 additional egg yolks, 1/2 cup sugar and 1/4 teaspoons salt in a saucepan. Slowly add 4 cups whole milk, then cook this mixture on the lowest setting while stirring constantly until it reaches 160 F.
Strain the mixture, and mix it with vanilla extract, nutmeg and the alcohol of your choice. Chill the eggnog for at least three hours before completing the next steps. Prior to serving, beat 1/4 cup heavy cream into soft peaks, and incorporate it with the egg mixture.