Chill glassware if desired: Coat the outside of a glass with water and freeze until serving time. Or, freeze dry glassware for 2 to 3 hours before serving.
To coat the rim of glass: Run a lemon wedge around the top of a glass. Then, dip the top of the glass upside-down in a shallow dish of sugar.
Combine cognac, orange liqueur, and lemon juice in a cocktail shaker. Fill shaker with ice, cover, and shake until outside of shaker is very cold, about 20 seconds. Strain cocktail into prepared glass and garnish with an orange twist.
Cognac or brandy: Cognac must be made in the Cognac region of France. Brandy, however, can be made anywhere. Hennessy, Korbel, Presidente, are all fine choices for a mixed drink.
Orange liqueur: Triple Sec, Cointreau, or Grand Marnier.
Glassware: Serve a Sidecar in a coupe glass or a small martini glass.
Sugar rim: Spread some sugar on small plate, then rub a lemon wedge around the rim of chilled martini or coupe glass. Tilt the side of the glass in the sugar to lightly coat the outside rim of glass.
Boston Sidecar: Reduce cognac or brandy to 3/4 ounce, add 3/4 ounce light rum, and substitute 3/4 ounce lime juice for the lemon juice.
Chelsea Sidecar: (aka Delilah or White Lady) Uses gin instead of cognac or brandy.
Pisco Sidecar: Substitute 1 1/2 ounces Pisco brandy for the cognac.