“How to survive your Trump meeting,” as an American lobbyist who advises foreign governments calls it, has become a cottage industry for lobbyists, consultants and national security experts in Washington. That’s according to interviews with a dozen government officials, diplomats and advisers. Most of these officials were granted anonymity to speak openly about how foreign governments manage Trump.

Even Ukrainian President Volodymyr Zelenskyy and his team prepared assiduously, hearing from key Republicans on Capitol Hill what amounted to a ‘Trump 101’ crash course on how to engage with the president, according to three congressional staffers and two other people briefed on the matter.

That now infamous meeting went off the rails anyway — exponentially increasing the anxiety of other world leaders about taking part in Trump’s newest reality show, an unscripted Oval Office get-to-know-you session featuring several Cabinet officials and playing out live before the White House press corps and broadcast instantly around the world.

The Zelenskyy meeting “was a real ‘oh shit’ moment for other leaders,” said one senior U.S. congressional aide familiar with the planning that went into that meeting. “They saw this public gauntlet they’d have to run. How do I avoid the Dumpster fire Zelenskyy fell into?”

Managing Trump is nothing new for foreign leaders who saw how the U.S. president operated during his first term. But the efforts to coddle a lifelong public performer, who can shift quickly from charming to contentious, have intensified since Trump took office for the second time in January, noticeably more confident and far less restrained in his approach to the job.

“What Zelenskyy went through was a huge lesson learned for other world leaders. Without a doubt, everyone’s been studying that really closely,” said another American who engages with the Ukrainian government on how to manage U.S. ties.

Japan’s new prime minister, Shigeru Ishiba, the second head of state invited to the White House after Trump’s inauguration, prepared for his early February visit by studying graphics showing Japan as the top foreign investor in the U.S. and brainstorming with aides about what demands Trump might make, Ishiba’s aides said at the time. When asked by reporters during his Oval Office sit-down what he thought of the president, Ishiba said, through a translator, that Trump’s television career made him “intimidating” but that he was “powerful” and “sincere” in person.

Carney, whose condemnations of Trump’s bullying “51st State” rhetoric propelled his Liberal coalition to an unlikely electoral victory this spring, spoke with several official and informal advisers in the run-up to his post-election White House visit in early May. One person who spoke with the prime minister, granted anonymity to discuss the private conversation, said they counseled him to distill his message into a couple clear phrases and repeat them as needed.

“With Trump, you want to make sure there is one core sentence, even two to three core sentences you are going to find a way to get out no matter what,” the person who advised Carney continued. “And you don’t need to talk that much. Let him speak.”

Carney followed the advice, emphasizing that Canada was “not for sale” but that the two countries were “stronger when they work together.” It proved effective in lowering the temperature: Trump complimented Carney’s initial statement and, shortly after the prime minister left the White House, described the conversation as a “great meeting” with “no tension.”

The person said they gave the same advice to Norwegian Prime Minister Jonas Gahr Støre before his White House visit in late April.“The reason the Zelenskyy meeting went so badly was Zelenskyy was trying to spar like an equal,” they said. “That is not allowed in the meeting.”

The risk of entering Trump’s lion’s den can be worth the reward for world leaders. Trump pared back his musings of acquiring Canada as a 51st state after the meeting with Carney. Finnish President Alexander Stubb, who traveled to Mar-a-Lago in late March just to play a round of golf with Trump, later convinced the U.S. president to reverse a decision on building icebreakers and purchase those ships from Finland.

South Africa’s Ramaphosa, who similarly tried to connect with Trump over golf by bringing South African golfers Retief Goosen and Ernie Els with him to the White House, received a harsher treatment. Trump, eager to highlight unfounded allegations about a “genocide” targeting South Africa’s white farmers, turned down the lights and played on a television wheeled into the Oval an unsourced video of what he said were gravesites.

Forced into a defensive posture, Ramaphosa expressed uncertainty about the scenes depicted but did not directly criticize Trump, even as he tried to dispel the notion that a genocide was occuring. However awkward his meeting, the South African leader, unlike Zelenskyy months earlier, managed to avoid a bigger blow-up.

Brian Clow, former Prime Minister Justin Trudeau’s top adviser during Trump’s first term and the early days of the ongoing trade war, revealed the blueprint for dealing with the president.

“Even if Trump says some outrageous things, you’ve got to choose if you’re going to interject or disagree — because it may be counterproductive in the long term if you get into too much of a back and forth.” Translation: don’t get Zelenskyy-ed.

Clow’s next piece of advice: vibes matter. “You’ve got to prepare for the overall tone and approach that you want to take,” Clow said. “That can be just as important as the policy issues.”

He suggested calling up the White House in advance, Clow said: “Scope out how conversations might go, what could come up. That can actually influence how the meeting itself goes.”

But preparation can only go so far with a U.S. president famous for unpredictability, Clow said. In March, Trump raised an obscure 1908 border treaty with Trudeau as he mused about erasing the border between the two countries. Trudeau was forced to deflect in the moment.

The big takeaway:

“Tread carefully,” Clow advised anybody who walks into the Oval Office. “This is Trump’s show, and you’ve got to let him do his thing.”