Monday marks the start of the new tax year, when many are thinking about their finances for the 12 months ahead.
For those planning to ask for a raise, buy a new car or move house, former crisis negotiator Lance Burdett has two pieces of advice.
"The first one is you must keep in control of yourself," he told Easter Monday host Susana Lei'ataua.
"The way to do that is to slowly breathe out through your nose as slow as you can, and when you do that, all of a sudden you're in a calm place."
The second piece of advice was for people to prepare what they wanted to say ahead of time, Burdett said.
That was a rule he lived by while working as a crisis negotiator, but it applied to other difficult conversations too, he said.
When asking for a pay rise, for example, the employee should think about what they brought to the company and their achievements and strengths.
"Why do you deserve a pay rise? What makes you different? What makes you stand above the rest?
"Have two or three key bullet points to keep in mind - don't drop them all at once, just slowly release them out across the conversation you're having."
Burdett trained with the FBI and spent 13 years as a crisis negotiator with the police.
Most famously, he was head negotiator on the Napier siege and the Paremoremo prison hostage situation.
In crisis conversations, the rule was "two ears, one mouth" - the other person should be doing most of the talking, he said.
However, when requesting something, the opposite applied - the person asking should speak the most.
"But remember, we don't want to get it all out at once. Slow the conversation down, slow your breathing down and make them want to ask you questions."
When making a purchase - for example, buying a house or a car - there was usually "a bit of wiggle room" on the listed price, Burdett said.
He encouraged people to negotiate by asking questions, like "What's the best price you can do for me?"
The hope was that both people came away from the transaction feeling as if they had achieved their aim, rather than thinking about "who's won and who's lost".
However, Burdett had a word of warning for those looking to buy a new house this year: never lowball your first offer.
"The worst thing you can do is to go too low - if you insult somebody, that gets their defences up. Once their defences are up, you have great trouble breaking through from there."