“Have you smelled this?” My fiancé held up the jar of salsa I’d bought and sniffed it suspiciously. “This tastes like roasted garlic, not medium. I think they put it in the wrong jar!”

“Oh,” I said with a shrug, dipping in a chip. “Maybe that’s why it was marked 50¢ off.”

If a team of counsellors were monitoring our flat with hidden cameras, they might calculate that 73 per cent of our sparring is over salsa. Alan insists on a particular brand of fancy organic salsa that costs $5 for a tiny jar. I, a much more reasonable type, am happy with whatever’s on sale. It’s like the man never heard of comparison shopping.

When I spoke to some actual relationship experts, I found out that our argument isn’t really about salsa. It’s about money, the most common source of disagreement of all, according to studies. And money arguments, of course, are about much, much more.

“Money comes up every day, so there’s a lot of grist for the mill,” says Dr Howard Markman, a professor of psychology at the University of Denver and a co-author of Fighting for Your Marriage. “It’s a magnet for hidden issues: power, control, respect, family of origin and trust issues.”

In this age of melting superannuation and investment accounts, it’s even more front and centre. The good news is, with some practical tools and a little finesse, couples like us – and you – can be on our way to a sweeter love life and a fatter bank account. No government handout needed. “People can waste a lot of time mucking around with the emotional side of money, when it’s much more efficient to treat your money like a business and solve the problems,” says Christine Larson, the co-author of The Family CFO: The Couple’s Business Plan for Love and Money, which she wrote with certified financial planner Mary Claire Allvine.

So let’s step out into the money minefield. Time to defuse the danger.

The investment mess

A Money magazine survey found that 73 per cent of men claim they’re in charge of the family’s investments. That survey came before this year’s worldwide economic crisis – lots of people now don’t even want to open bank statements, let alone take charge. Two-thirds of husbands proudly call themselves the couple’s biggest risk takers. Which is what got the financial markets into trouble.

THE ANSWER Don’t do anything major without professional advice. Women tend to be more careful with money, says family therapist Dr James Morris. Play to your complementary strengths.

Dr Jonathan Rich, a clinical psychologist and the author of The Couple’s Guide to Love & Money, calls cautious people “Bankers” and risk-lovers “Gamblers”. The Banker should make sure all possible savings are being made and play devil’s advocate if the Gambler argues for a move in a new direction. If the Gambler has a big idea of investing in windmills, then they must convince the Banker that they have examined the pitfalls.

Compromise is best: cautious, standard investments get most of the pie, with a small slice for risk.

The grocery store

“Beware the olives debate,” says Neil Chethik, the author of VoiceMale, a book that surveys hundreds of men on marriage. “The arguments are usually over the smallest items. Somebody buys a jar of olives that’s not on the grocery list. The other partner buys nothing that’s not on the list and buys everything as generic as possible.” According to Morris, guys are typically on the same side as my man on the salsa because they’re not usually in charge of the household budgeting. Women usually do the shopping, he says, “and men are somehow seen as not as capable, and so they’re going to just follow their gut, no pun intended”.

THE ANSWER Go food shopping together a couple of times. It’s true, your little splurges aren’t going to break the bank. But a joint expedition can help bring peace and understanding. Alan and I have fun – he convinces me to try exotic Spanish cheeses; I show him how to compare the price of frozen peas. “The advantage with money, as opposed to other relationship issues, like affection, is that it can be negotiated in a very concrete way,” says Chethik.

The new couch

Just as many women as men make big-ticket purchases without consulting their partner, says syndicated personal-finance columnist Michelle Singletary.

“Curtains can cost a fortune, and a wife shouldn’t spend a couple of thousand dollars on something he hates!” she says. “If you’re going to spend that kind of money, you both ought to be happy with that purchase.”

In her book, Your Money and Your Man, she writes about the three Cs: communication, compromise and common goals.

THE ANSWER Singletary’s rule: you must discuss all purchases that exceed an agreed-upon amount. In her house, the threshold is $200. “Anything that’s going to have an impact on your budget, you absolutely ought to have a rule. No purchase can be made without both of us agreeing to it,” she says, adding, “It took us seven years to buy our dining-room set!”

Your cheating card

You hide the bill from that one credit card. She cuts the tags off her new outfit. This is called “financial infidelity”. A survey conducted by Redbook magazine and the website lawyers.com found that 29 per cent of partners have “cheated” financially. One in four said that lying about money worried them more than lying about sex.

THE ANSWER Open the books. You should peek at bills she pays, and vice versa. “If a couple was having trust issues with cheating, you wouldn’t say that separate bedrooms were the answer,” says Singletary. “I think the same thing about separate accounts.” But some “mad money” from your own salary that isn’t busting the budget should be allowed, says Larson. “Each person has his or her own departmental budget.”

The cutoff notice

It doesn’t matter who’s in charge of paying the bills; when they don’t get paid on time, both partners suffer.

THE ANSWER Larson advises appointing one person to be in charge of cash flow and the other to oversee investments (brass nameplates optional). “Set your goals, agree on your priorities and have a cash-flow and a net-worth statement that you look at every month,” she says. If neither of you is particularly detail oriented, join the 21st century and move your bill payments and investment contributions online.

Dreaming that dream

My fiancé is now my husband and I have the usual wishes about life: buy a home, plant a garden, travel the world, have flexible work schedules, and spend time at home with our wonderful, perfect future babies. How do you get on the same page?

THE ANSWER More paper. Each of you writes down your top three goals in these three areas: work, children, retirement (no peeking). Then compare. “You need a vision together as a couple,” says Rich. “What kind of balance do you want between leisure and work, and how do you envision that changing?”

Now you have a starting point for negotiation and a reference point in the future. Cold and businesslike? Hardly. “It’s actually quite romantic, in a way,” says Larson. “This is what brings couples together in the first place, because they want to achieve the same things.”

Alan and I tried this approach when we planned our honeymoon. Over lunch in the park, we sat down with a map, made out a budget and trimmed down our itinerary to focus on a few favorite countries. The planning was fun – it stopped being about who’s going to get their way and started being about what will benefit the two of us. And that’s what makes a strong team – in business or in love.