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When Jeff Nussbaum stood up to deliver a toast at his sister’s wedding, he opened with this doozy: “The first time Scott showed up at the door, I thought, ‘J.Crew usually just sends a catalog.’ ”

That single line reveals two facts about Nussbaum. He has an extremely preppy brother-in-law and, man, does he know how to start a speech.

Figuring out just the right thing to say is what he does professionally as a partner in the West Wing Writers. The communications firm, with offices in D.C. and New York, offers assistance to anyone who needs to stand behind a lectern — using techniques honed while working in the White House.

“With Clinton, it was clear he really enjoyed it. He welcomed the opportunity to tell stories,” says Vinca LaFleur, another West Wing Writers partner. She recognizes that most people don’t feel quite so comfortable as the center of attention. But at some point, whether it’s a wedding, a milestone birthday or a retirement party, everyone has to speak up, she says.

And there’s one easy way you can improve on the former president’s technique: Keep it short.

“The best material is wasted if the overall effect is ‘that was long,’ ” Nussbaum says. For most speeches at family and work events, five minutes is plenty. Since a good pace is about 150 words per minute, LaFleur adds, that means 750 words maximum.

If you have no clue what any of those words should be, start by thinking about why you’ve been called upon to speak. Are you the sister? The boss? The best friend? Consider what you can share based on that identity that no one else could, LaFleur says. (A corollary from Nussbaum: If you haven’t been called upon to speak, but after a few drinks you want to, don’t.)

For a basic structure, think of a theme — such as, “three things I love about this person,” LaFleur suggests — and thread that through the speech. Ideally, you can conjure up more than platitudes and offer a story or two to illustrate your point.

Saying someone is “kind and generous” can’t compare to an anecdote about how that person brought you soup and cheesy movies when you were recovering from surgery.

Certain stories, however, are better left untold. Nussbaum has this rule for figuring out what’s appropriate in a wedding toast: “In order to stay in the bounds of propriety, deliver it like a eulogy for two people who are still alive. The humor should be appreciative rather than embarrassing.”

Also stay away from hinting at inside jokes. Either it’s something you can share with the whole group, or it’s not, he adds. Unsure whether a line really works? Take a lesson from the pros and test out your material ahead of time.

“ ‘Authentic you’ doesn’t mean ‘unrehearsed you.’ Some things will sound awkward and dorky,” Nussbaum says. “It’s always good to have a basic reality check.”

Maybe you’ll find out you should pause after a joke, or remember to bring tissues.

“I’m a weeper. I know this may happen,” LaFleur says. So she comes up with a plan for what to do if her voice breaks, or if she needs a moment before she can continue.

Memorizing is tough — and chances are, you won’t have a teleprompter to rely on — so there’s nothing wrong with having a cheat sheet, Nussbaum says. He just recommends jotting your thoughts on small index cards rather than a flimsy piece of paper. (“If your hand shakes a little, paper shakes a lot, and it can become a distraction,” he says.)

If you start feeling nervous, remember that you’re not delivering the State of the Union, and there isn’t a team of talking heads waiting to dissect every word on CNN.

“The audience is on your side. They will root for you,” LaFleur says. And everyone will agree with your final position: arm out, raising a glass in the air.

Props Prep

Before you say a few words, arm yourself with a few things:

Index cards. They make the best cheat sheets and fit easily in a suit pocket.

Tissues. Even if you’re not typically a “weeper,” you never know when tears may strike.

A glass. It’s tough to toast without one. How full it is shouldn’t matter: If you keep your speech short, you won’t have a Marco Rubio-esque water-bottle moment.