The main idea behind a well-stocked bar is two-fold: 1) the majority (say 90%) of cocktails and drinks are variations of a few recurring combinations and 2) having a half-dozen-to-a-dozen spirits on hand, plus some common mixers allow you to make to order a good number of cocktails or mixed drinks your guests might want.

We can imagine a range of bars, from the full bar that a drinking establishment will have to a well-stocked bar for the home to abbreviated, even minimal liquor cabinets. Most likely a complete bar will be out of the reach and even interests of most home bartenders. Traditionally, then, the well-stocked home bar consists of the following:

Classical Well-stocked Bar
Spirits: Vodka, Gin, White Rum, Tequila, 3 Whiskeys (Bourbon, American/Canadian, blended Scotch).

Mixing ingredients: Triple Sec, dry Vermouth, Rose’s lime juice, sweet Vermouth, Angostura bitters, Grenadine

Garnishes: Cocktail olives, Maraschino cherries, Bar salt (kosher salt works), Cocktail onions

Mixers: Tonic water, Club soda, Soft drinks (Coke, Sprite or 7-Up, Ginger Ale), Orange, cranberry, tomato, and grapefruit juice

Fresh ingredients: Lemon and lime for garnish, mint leaves

Each is listed in order of frequency of use.

So is this what you should buy? Depends.

On budget first of all. Even if you don’t go for top shelf, buying fifths of all the above will cost a pretty penny. Say you’re a struggling twenty-something or a sometime cocktail drinker who wants to have spirits on hand when friends drop by but doesn’t feel the need to be a completist. I can imagine you getting away with the following basic home bar, in order of purchase:

Basic Bar
Vodka, Gin, Triple Sec, dry Vermouth, Bourbon, and White Rum or Tequila, sweet Vermouth

Fresh lemon and lime on hand, Tonic Water, Cranberry, Olives and maraschino cherries, Rose’s Lime, Club Soda, Orange Juice

Or, if you’re being particularly budget-conscious, try:

Minimal Bar
Vodka, Gin, dry vermouth, tonic, cranberry, Triple Sec, olives, Rose’s, soda.

It’s barebones, but there are still a number of drinks you can make with that.

Just as important as budget will be the crowd you’re serving for. American, Canadian, or Irish whiskey drinks and scotch drinks are not nearly as popular as they once were, and if your friends are under the age of 40, you may be able to safely omit. You’d be better off buying a single malt scotch for your scotch-loving friends than trying to accommodate the rare Rob Roy, Rusty Nail or Presbyterian requests.

Finally what you stock will vary by what you like to drink and serve. I love sidecars, so I keep brandy on hand. If you like Alexanders or Chocolate Martinis, you’ll stock crème de cacao. Et cetera. As a general rule of thumb, if you’re looking to build on the well-stocked bar, I’d add brandy, Grand Marnier, and two or three cordials of choice, including one sweet liqueur (Kahlua, say) and one bitter (such as Campari).

Ultimately these rules of what to stock are there primarily to guarantee you can make a cocktail or drink to order. The well-stocked bar is a great enabler for entertaining, particularly for occasions when you have more formal affairs or are entertaining guests beyond close friends.

But that’s the only reason for the rules, such as they are, and they can be broken without much harm. After all, you know your guests better than anyone.

Cocktail aficionados will likely have their preferences for stirred or shaken martinis, manhattans or other cocktails. But many might wonder: what’s the big deal? when should you shake and when should you stir?

Sometimes the ingredients themselves dictate what to do. Drinks with cream or heavy liquids needs shaking to fully mix them. (I should note the exception of those which are meant to be served not fully mixed, like the White Russian or the Mudslide. Just pour these directly into an old-fashioned glass.) Even cocktails with fruit juice components, like the cosmopolitan or the daiquiri, can use with a good shake.

But the choice is also a matter of preference. Shaking has an impact beyond mixing the ingredients, after all: it chills the drink and waters it down more than stirring. If you want drinks especially cold (as I generally do with cosmos), be sure to shake vigorously. Do it enough and little ice crystals will float in your glass as your pour.

Alternately, if you don’t want your liquor watered down, stir your cocktails then strain into the glass. That’s the idea behind stirred-not-shaken martinis and the like. Asking for them is a macho statement of sorts to take the spirits at full-strength, since cocktails are simply (or at least mostly) booze. Since I’m not a macho guy and since I prefer gin to be quite cold, I take my martinis shaken. Then again, for vodka martinis, stirring is probably the way to go, since it keeps whatever subtle flavor the expensive vodka has from being watered away.