Ingredients:
Garnish: lemon peel
Glassware: Old-fashioned
Yield
one cocktail
Method
Add large ice cubes to your glass, pour the Drambuie and Scotch over the ice, and gently stir. Express the lemon peel over the drink and place it on the ice as a garnish.
Wikipedia notes many variations:
The Rusty Bob, which substitutes Bourbon blended Scotch whisky
The Rusty Ale, in which a shot of Drambuie is added to any beer, served without ice.
The Smoky Nail, which uses Islay whisky in place of blended Scotch whisky.
The Clavo Ahumado (Spanish for "smoky nail"), using mezcal instead of blended Scotch whisky.
The Railroad Spike, often served at brunch and made with approximately four parts cold brew coffee to one part Drambuie in a tall glass over ice.