Every day presents a series of negotiations. There's the small stuff, like getting the kids to finish their dinner. And the big stuff, like negotiating your salary or business deals. Then there's the really big stuff, like negotiating the release of hostages from armed fugitives.

No matter what you're negotiating, the basics to doing it well stay the same. That's according to Christopher Voss, who wrote the book on negotiation. Literally.

The former FBI hostage negotiator recently published Never Split the Difference, a best-selling business book on business negotiations. The 24-year FBI veteran is also the CEO of consulting firm Black Swan. He draws from his high-stakes hostage negotiation experience to teach the same skills to the business world.

Voss says effective negotiators play into emotions instead of logic. They have high emotional intelligence, meaning they can identify the other side's emotions and learn how to influence them.

While influencing emotions might sound like it requires some mind-reading wizardry, it doesn't. Like mastering any skill, becoming an effective negotiator requires patience and practice. And it also takes lots of listening. That's where the 90-second rule comes in.

Finding the 90 seconds of solid gold

Speaking at a recent IVY Ideas Night, Voss boiled down his tips for effective negotiation. When entering a hostile situation, Voss says, he always lets the other side go first.

Of course, we've all heard this advice before. We're told to never be the first to name a price, number, or salary. The problem is, both sides follow this same rule. Which makes things awkward, because no one's talking about money, when the whole point of some negotiations is to talk about money.

Instead, Voss encourages a tactic he calls listening between the lines. Still let the other side speak first. This lets them own the process. Or rather, it lets them think they're owning the process. Then listen hard. Eventually, they're going to give you a nugget of something you can use to steer the conversation in the direction you want it to go.

All this happens in the first 90 seconds. Even if the negotiation ends up taking two hours, Voss says these 90 seconds are critical for negotiation success.

"You have to shut up," he says. "Wait for it. And listen for it. And then the other side is going to give you that solid gold. When they say something that works, you go 'brilliant!' And you make a deal."

People rarely come out and say exactly what's on their mind. But with the right strategy, you can get them to lead you there. Try to listen for what they are implying, Voss says. If he listens to someone long enough, the person will make references to it. "As soon as I pick up and feed back to you what you're implying, then you want to talk to me even more. Then that bond gets even stronger and stronger."

Shutting up and listening is a hard skill to learn. Knowing what to listen for and using that information to shift the conversation is even harder. But, Voss says, with practice, anyone can leverage this strategy to negotiate better. You won't get it right the first time, but keep trying. "You learn from trial and error," he says. "There's no other way than making mistakes."