A French 75 is a great cocktail for entertaining because it's easy to make and it's customizable: You can add a small amount of your favorite liqueur (for example St-Germain, Chartreuse, Galliano, Amaretto, Campari, Benedictine, Italicus, etc.) to the base recipe to tweak it to your (or your guests') preference.
Pour your favorite sparkling wine into a chilled Champagne flute.
Add the remaining ingredients into a cocktail shaker and shake briefly, but vigorously. Strain immediately into the Champagne flute over the sparkling wine.
Squeeze the lemon oils from citrus peels over the drink and hang a pigtail lemon peel over the rim before serving.
To customize the drink: Add 1/4 ounce of your favorite liqueur, such as St-Germain, Chartreuse, Galliano, Amaretto, Campari, Benedictine or Italicus.