Sharp, balanced, and old enough to know better. This is a proper whiskey sour—no neon-yellow bottled mix anywhere near it.
If using egg white: dry shake all ingredients (no ice) for 15 seconds to build the foam. Add ice and shake hard for another 15 seconds. Strain into a rocks glass over fresh ice. Drop two dashes of Angostura on the foam and drag a toothpick through for the classic swirl.
No egg white? Just shake with ice, strain, and serve. Still excellent. Still miles ahead of anything from a bottle.
A note on whiskey and gluten: distilled whiskey is generally considered gluten-free by the distillation process. If you are highly sensitive, choose a whiskey distilled from corn (like many bourbons) or a certified gluten-free whiskey for extra confidence. Trust your body, not the internet.