Classic ingredients, classic balance; this drink truly deserves the name. The earliest recipes specify curaçao or triple sec, but other orange liqueurs can work if you tinker with the proportions a bit.
Shake with ice and strain into a chilled cocktail glass. You can rim the cocktail glass with sugar for a kick of sweetness, but remember: as with all rimmed drinks, be sure to only wet and rim the outside edge of the glass, not the inside or top. Getting little chunks of sugar clumped up in your drinks is gross!