The liqueur smooths and wonderfully combines with Scotch whisky. The proportions of Scotch to Drambuie vary wildly and are a matter of taste. However...
My riff on the Rusty Nail uses one dash of Angostura Bitters and two dashes of Black Walnut Bitters to lend a toasty, nutty complexity that complements the Scotch and sweet liqueur. Rusty Walnut, anyone?
Rusty Walnut - 45ml Blended Scotch - J&B Rare or Monkey Shoulder, 15ml Drambuie, 1 dash Angostura Bitters, 2 dashes Black Walnut Bitters. Serve in a Gibraltar Glass over a 1 inch ice cube