If anything falls under the category of Mandatory, it's having a properly stocked bar. Here are the essentials.
First and foremost is booze. There is no bar without alcohol, and you're not properly prepared to entertain without the Big Five: vodka, gin, whiskey, rum and tequila. But there are a lot of options out there. Which brands to stock? (Note: We highly recommend stocking multiple selections of each.) And what you select for your home bar says quite a bit about you, so here's what we've come up with.
Let's Party: Absolut, Tanqueray, Captain Morgan, Jack Daniels, Jose Cuervo
Casual Class: Bombay Sapphire, Patron, Mount Gay, Jameson, Grey Goose
You're Not Invited Back If You Ask for a Mixer With This: Crystal Head vodka, Johnny Walker Blue Label whiskey, Hendrick's gin, Tres Generaciones tequila, Havana Club Maximo Extra Anejo rum
Drinking straight liquor is a "neat" trick, but it leads to very short, messy affairs. What you need is a good selection of mixers. We'll start by presuming you already have ice. You're also going to want soda: cola and something clear and lemon-limey at the bare minimum. Seltzer also is appropriate. Fruits and juices are equally important. Put lemons, limes and oranges on the menu, and you'll also want orange juice and cranberry juice. But those are the basics. People won't know you've upped your bartending game until you bust out the bitters, an herb-based liquor that packs a powerful punch when dashed into a cocktail, so one bottle should last you quite a while. The most common and readily available are Angostura bitters, and a bottle will set you back only about $10. Well worth the investment.
Anyone who tells you that a drink will taste best when served in the proper glass is pretty much full of it. A red plastic cup will work just as well as anything else. However, the proper cocktail glassware always looks best, and adds an air of sophistication to your imbibing endeavors. There are just two essentials for a proper cocktail bar: the martini glass and the tumbler (and if you're thinking about wineglasses, all you need is a Burgundy glass and a Bordeaux glass). If you want to go super-pricey, top-of-the-line crystal, Riedel is your brand, but Schott Zwiesel offers a much more affordable range of German crystal glassware that can't be beat when it comes to quality-to-price ratio. Pick up a set of all-purpose tumblers or high-ball glasses and a set of classic or contemporary martini glasses, and you're all set.
Shake It Up
The most important tool (and perhaps the only real necessity) of a proper home bar is the cocktail shaker. There isn't much to it, as it's basically just a lidded cup, but there is a fair amount of showmanship involved in shaking up a good libation, so you want your cocktail shaker to look good. While you can go the uber-high-end route and buy a sterling-silver mixer from Tiffany's, you don't have to shell out big to look like you did. The Italian design house Alessi made a beautifully crafted, stainless-steel Boston shaker with a satin finish on the inside that will have your guests impressed.
We don't recommend eating from the nut bowl at a bar. There's no telling whose hand was in there 10 minutes ago. At home, however, you control the food supply, and it's nice to set something out for your guests to snack on. Pretty much anything not stale will do -- no one came over for the salty snacks -- but all snacks were not created equal. A can of Planters mixed nuts: fine, but meh. Surprise your friends by making your own popcorn, which is surprisingly simple. In the bottom of a pan, coat a layer of kernels with olive oil, heat under a lid and stop when there's a two-second delay between pops, or they just look done. Then season with anything you like. (We recommend cayenne and salt to keep everyone thirsty.) If popping corn and shaking cocktails is too much to handle, set out some slightly sweet, slightly salty and very delicious fresh Marcona almonds from Spain.