Johnson said people should also tell their boss ahead of time what they want to discuss prior to the meeting.
"Not only does this give you both time to prepare, it can be an easier way for you to broach the topic."
Roman Rogers, regional general manager for Hudson New Zealand, said many businesses had an operating rhythm which meant there were quieter times of the year or week which might be a better time to talk to the boss.
He said it was probably best to avoid first thing on a Monday morning and last thing on a Friday when managers often had others things on their mind.
Rogers also warned that the New Year may not be the best time to ask for a pay rise.
"It may not always be, because different organisations have different financial cycles."
Some companies have very structured ways for reviewing pay which only happen at a certain time of the year.
"I don't think it is always the best time of the year. It is more about understanding the rhythm of the organisation."
Come prepared
Jason Walker, managing director Hays New Zealand, said good preparation was vital.
"Prepare a list of your recent achievements that exceed your objectives - you may need to look back at your original job description.
"Also list any changed or rising work volumes or duties you're now undertaking and consider projects you've been involved in.
"Then list the resulting benefit to the company of your results."
Walker said the aim was to provide strong evidence to support the value you provide to the company.
"Back up your case with evidence from a recent salary guide to demonstrate that the salary you are asking for is in line with current market rates."
Rogers said it was a good idea to run your arguments past a friend first.
"Use a friend to ask "does this make sense?". Make sure you have got really strong evidence around what you are worth."
Rogers said it was more relevant to have data from outside of your organisation than arguing based on what the person sitting next to you was getting.
Johnson said it was vital to understand your worth to the company and the value that you add through your role.
"There really is no point in asking for an increase if you are not producing value for the organisation."
If the conditions mean it is tough to ask for a pay rise there may be other non-financial rewards that you could look at.
Don't get personal
Johnson advised people to be professional when asking for a pay rise.
"This is business, so treat it accordingly. It isn't personal, so try not to make it personal.
"This is about you feeling you are adding value beyond your current remuneration and not that you need to purchase a new house.
Johnson said asking for a pay rise was a huge deal for some people so emotions may come into play.
"Be rehearsed and know what you want to say. Don't get emotional or threaten to leave. Stay professional."
Negotiate but keep it realistic
She urged people to be realistic and prepared to negotiate.
"Don't back your employer into a corner. You will achieve much more by open communication, which includes listening to your employer.
"If you don't get what you want the first time, I suggest you get a plan to work towards. Find out what else you need to achieve and/or get a date that your remuneration can be reviewed."
Biggest mistakes
Not asking or assuming that your employer should simply know that you believe you are underpaid is probably the biggest mistake people can make, Johnson says.
"This can lead to avoidable dissatisfaction or lack of engagement."
She also advised against taking your employer by surprise.
"Obtaining courage at the office Christmas party after a wine or two is never a good time to ask for an increase."
Nor is offering to do more for more money.
"Firstly, you are asking for an increase based on current performance, not predicted.
"Unless you are under worked, offering to do more could be a fatal error, particularly if you don't have capacity.
Rogers said for him the biggest mistake people could make was using another offer to bargain with their boss.
"I get how some people could see that as a good idea. But that is probably the biggest no no ever."
Rogers said doing that could leave your direct manager feeling black-mailed which could leave lasting impact on your relationship with them
That could have unintended consequences like affecting future pay rises or promotions.
It could also damage your brand, if you went for a job at another organisation and then turned it down, which may dent your prospect of a job there in the future.
For Walker the biggest mistake was people not backing themselves.
"Not using your accomplishments and the value you add to the organisation as the basis of your negotiation is the biggest mistake we see.
"You need to clearly demonstrate your worth to be in a stronger negotiating position."
He also advises against getting an offer from another employer and using it as leverage to get a pay rise.
"It doesn't work and I wouldn't recommend doing this. It can be a clumsy negotiating tool that usually backfires."
Walker said it could also damage your reputation in the industry, particularly if it is a niche role or industry where people know each other.
