For a smoother texture, consider using simple syrup instead of superfine sugar. Adjust the sweetness to your preference by adding a touch more or less sugar. The quality of your whiskey will greatly influence the final taste. Choose a whiskey with notes that complement the citrus, such as a spicy rye or a bourbon with caramel undertones. Freshly squeezed lemon juice is essential for the best flavor. Avoid using bottled juice, as it lacks the brightness and complexity of fresh juice. Chilling the cocktail glass beforehand will help keep your drink colder for longer.