I remember my early years of drinking; cocktails were not really a thing. Multicolored and saccharine sweet, the cocktails of that era often bellowed an unnatural hue; they were accompanied by an umbrella or clever little plastic dolphin. The spirits used for these cocktails were selected because of price, availability, or in some cases, they were just unpleasant to consume on their own. So even if my friends and I were trying to be sophisticated by ordering a Manhattan or an Old Fashioned, invariably the cheapest of blended whisky would be used to create them.
Thankfully, things have evolved over the last thirty years. Bartenders now see the benefits of using great whisky to make great cocktails. Using great spirits in cocktails does not condone anyone, bartender or otherwise, to pour twenty-five-year-old Macallan into an Old Fashioned, although I bet it would be lovely, but it does mean using aged single malts is a good idea. These are a few suggestions to smarten up what would be fairly ordinary cocktails:
Old Fashioned: 15-year-old Glenfiddich. This is the best all-around whiskey for an Old Fashioned; it is a rich and well-balanced whiskey with a bit of spice and plenty of fruit and sweetness.
Manhattan: Hudson Manhattan Rye. It's as if they named it specially! This is an example of traditional rye whisky making, and it makes a brilliant Manhattan. Don't use cheap vermouth; use Antica Formula or Lustau Vermut Rojo.
Dry Martini: use a high-quality gin like Ki No Bi or export strength examples from Tanquary (Tanquary 10), or Beefeater (Beefeater 24).
Wet Martini: As well as high-quality gin, make sure the white vermouth is of the highest quality, such as Regal Rogue Lively White or Vermouth Premium del Professor.
Cosmo: Rather than using triple sec or even Cointreau, use Grand Marnier. Added to that, use a vodka that is flavoursome (not flavoured), pure vodkas are good, but for a cocktail, a vodka with some flavor makes a cocktail with greater depth. I'd suggest Black Cow Pure Milk Vodka or Brocken Clock Vodka.
Tequila Slammer: The reason for salt and lemon with a shot of tequila is to hide poor quality tequila. There are some fantastic tasting, well balanced tequilas out there and are worth simply pouring over ice and savouring. My top two at the moment are Gran Patrón Piedra Extra Añejo and Pancho Datos Reposado.
Above all, I believe cocktails are about experimenting. Over the years, I've put together some concoctions and while my friends were less appreciative of my endeavors, I thought they were delicious. Like cooking, if you use good ingredients, the results will also be good.