Many people do not consider Scotch whisky an appropriate liquor to mix in cocktails. Scotch is a flavorful drink, and oftentimes an expensive one, that there are a great number of "purists" who believe it should be drunk on its own or not at all. There are, however, a great many mixed drinks that can and are being made with Scotch. Below is a primer on using Scotch whisky in cocktails.
The Flavor of Scotch
Scotch whisky has a very dense, complex and strong flavor palette. It is earthier and peatier than other types of whiskey, and often tastes and smells of smoke to some degree. As with other whiskeys, there is also a semi-sweet malt character reminiscent of the grain it was distilled from, and of course the strong scent, taste, and feel of the alcohol content. This complex, layered flavor makes it more difficult to mix Scotch with other drinks successfully; any mixers need to allow the range of flavors in the Scotch to come through without clashing with any of them.
Single Malts and Blends
The basic types of Scotch are single malt and blended. Generally, single malts are more expensive, and are perceived as being of higher quality. They will have more distinctive and varied flavors than most blended Scotches, and as a result most people are disinclined to use them in mixed drinks. It is ultimately up to personal taste, although if the mixers in a cocktail will obscure the layered and subtler flavors of a single malt to the extent that it will be indistinguishable from a lower-priced blended Scotch, there is little point in using the more expensive whisky.
Scotch on the rocks is the most basic and common Scotch-based cocktail. The Scotch is shaken with ice, then poured into the glass over more ice, to both chill the drink and mix a small amount of water in and slightly dilute the strong flavor of the whisky. Ordering a Scotch and water is another way of achieving the same thing, but without the chilling effect of the ice. Scotch and soda is another common mix, adding the fizz and subtle flavor of soda water to complement the complex flavors of the whisky.
Scotch as a Substitute
Scotch can be used in many standard whiskey-based cocktails to replace other whiskeys. Whiskey Sours (one part whiskey, two parts sour mix, or more traditionally lemon juice, soda water, and half a spoon of sugar), Irish coffees (one shot whiskey in a cup of coffee), hot toddys (equal parts whiskey, hot water and lemon juice, and a spoon of sugar), and many other standard drinks can be made with Scotch. Not all of them will taste good with all Scotches, however. Especially since everybody's tastes are different, you will need to experiment with the particular Scotch you have in order to find which cocktail it can be substituted in successfully.
Recipes Made for Scotch
There are some recipes made specifically for use with Scotch whisky. The Whisky Royale, for instance, contains one part Scotch and a splash of apple schnapps, topped up with ginger ale and a slice of sour apple, turning the dark and complex Scotch into a component of a very light, crisp, refreshing drink. On the other hand, the Whisky Mac includes Scotch and green-ginger wine in equal parts to bring out the spicy, warming characteristics of the Scotch. Most of the drinks made for use with Scotch contain relatively few ingredients, so as to allow the signature flavors of the whisky to come through. You should make sure, however, to check the recipes you use do not call for a specific brand of Scotch other than what you have on hand, as the flavor may be significantly different.