David and Wendy have been dating for three years and are considering marriage. (Their names have been changed so they don't show up in the future in-laws' Internet search results.) They're compatible on many levels -- but money's not one of them.

"Wendy questions a lot of things that I purchase -- everything from my condo to a paper shredder," David says. "She takes some of the joy out of buying things, and it's not even her money that I'm spending."

Wendy says: "I hate to spend money, and when I do, I do a lot of research to find the best buy. It's difficult for me to understand and accept how he handles his money, when, with a little work saving $5 translates to two Metro rides."

It's the classic spender-saver conflict -- and they haven't even combined accounts or traded credit scores yet.

The most important relationship saver: Appreciation
If affairs of finance trigger door slamming and hand-wringing in your household, you're not alone. The matter-of-factness of account balances and ATM receipts belies the potent emotions that money conjures in many relationships.

But finances don't have to be a sore subject in your household if you know how to broach this touchy topic. If you're going to pour your heart into cultivating just one relationship building block, many pros agree that "appreciation" is the core concern to address.

"We all want to feel appreciated within business, within marriage, within any relationship; empirically, the research has shown it to be true as well," says Daniel Shapiro, psychologist, negotiation expert, and co-author of Beyond Reason: Using Emotions as You Negotiate.

Appreciation in this context doesn't mean "approval" or "gratitude" -- it's about understanding, respecting, and acknowledging the other person's point of view. To get to the heart of what someone feels, you've got to get into character -- their character.

As dorky as it may feel, role reversal works. Speaking as "I" (as in "I feel ...") forces you to consider your partner's perspective. Even if you don't agree with how they see things, their viewpoint has merit because, quite simply, it is how they feel.

Appreciation isn't a one-way concern -- you need to help others appreciate you, too, by providing the information that will lead to understanding, Shapiro says. (See more of his advice in "How to Get Your Way and Still Stay Friends.")

Crossing the spender-saver divide
To David, money represents opportunity. To Wendy, it's a source of insecurity.

They came to these realizations after having a conversation that was different from all previous ones: They explained to each other (no arguing, no defending) what informed the way they approached finances.

After paying his bills and funding his retirement account, David has half of his paycheck left to do with as he pleases. Wendy's take-home pay is nearly one-third less than David's, and her discretionary funds are just one-quarter of what she brings in. She also has student loan debt that weighs heavily on her.

With a deeper understanding, they've come to appreciate -- and even value -- aspects of the other's money handling ways.

"I get you now, and I respect you more"
David now seeks Wendy's cost-cutting advice before big purchases and is planning to institute a more formal budget that would allow him to achieve his long-term financial goals much faster. And Wendy is less anxious when David talks about upgrades he wants to make to his home or computer."Now when he buys something new I relax because I understand why it's not that big of a deal to him," she says.

Together they've even talked about how they would handle the family finances in marriage and agreed on ways to retain their autonomy while not impinging on one another's money style.

More advice (and fun!) for twosomes:

Dayana Yochim is the author of The Motley Fool's Guide to Couples and Cash: How to Handle Money with Your Honey. The Fool has a disclosure policy.