I lifted this from here and added my own expert comments:

1. Say “I love you” every day

Barbara De Angelis, personal-development expert: Say it as often as possible. There’s no reason to be emotionally stingy with the person you love.

Nancy Kalish, psychologist: I agree that it should be said often, but it should be said sincerely, so it means something. Not just “Good-bye. Love you.”

Poobomber, blog author: It beats saying “Fuck you, you stanky wanker” over pancakes every morning.

2. Play hard to get

Sam Yagan, dating Web site OkCupid, cofounder: Playing hard to get starts the relationship off on a deceptive foot. If you want your relationship to be based on trust, honesty, and communication, why would you begin it like that?

Greg Behrendt, coauthor of “He’s Just Not That Into You”: You shouldn’t play hard to get; you should be hard to get, because your life is so busy and fulfilling. My wife and I call it being a MOD – a moving object of desire.

Poobomber, blog author: Greg, your twatty acronyms and anecdotes about your wife are inspiring.  I’m screwing your wife by the way.  She didn’t play hard to get and we’ve been going strong for 6 years now, so obviously ‘playing hard to get’ is stupid.

3. Your spouse shouldn’t be your best friend

Pepper Schwartz, sociologist: I agree. I think you’re asking a lot of your marriage to have the level of confidentiality, truthfulness, and disclosure that a best friendship has. Your marriage can fulfill only so many roles.

De Angelis: I disagree. If your spouse isn’t your best friend, then what is he? I think it’s important that you not only love him but like him a lot, too.

John Gray, author of “Men Are From Mars, Women Are From Venus”: I have no problem with partners who are best friends, but you should have other close friends to confide in as well – especially when you are having relationship difficulties and need time away from your spouse. Don’t put all your eggs in one basket.

Poobomber: Does she help you lift couches when you move?  Does she watch the same shows as you?  Does she go out with you on a Friday night and have contests with you to see who can pick up the drunkest chick in a bar?  If she does, she’s your best friend.  If she doesn’t, she’s your wife.

4. Absence makes the heart grow fonder

De Angelis: A little bit of absence can help you appreciate your partner. Too much is dangerous. Relationships need connection, and it’s challenging to stay connected when you aren’t spending time together.

Schwartz: To a point – and then absence makes the heart go roaming. You need a steady diet of intimacy and the other person’s presence to remember why you’re in the relationship. If you don’t see each other often enough, you can start to lead parallel lives instead of lives that intersect.

Yagan: Absence can make the desire and lust for your partner grow. But it can also lead to stress in a relationship, because phone calls or text messages aren’t substitutes for real conversation.

Poobomber: Send them to the next room.  You’ll probably want to bone them by the time they get back right?  Is that how this works?  I dunno.  Out of sight, out of mind though too, right?  I tend to hump anything that happens to be near me, like couch cushions, coffee cups (don’t ask) and coworkers.  So I don’t think being apart from your lover is all that great of an idea, it opens up the possibility that I might become attached to an inanimate object in lieu of my partner’s absence.

5. You can learn to love someone

Judy Kuriansky, sex therapist: That’s true, depending on how you define love. You may not have the love-at-first-sight kind of love, but the deep companion kind of love – in terms of trusting each other and being a team – can develop over time.

Behrendt: No, that sounds like settling. I don’t believe in settling, because it’s not fair to the person you’re with or yourself. It’s not like settling on an apartment you don’t love but can live with.

Poobomber: They have college courses for this?  I dunno, the only thing someone should be ‘learning’ in their adulthood is how to cheat at taxes and how to get away with shit at work.  The last thing you want to learn is how to love someone.

Or are we talking about sex-love here?  In that case you should really know what to do with your penis or vagina, the mechanics are pretty simple but maybe if you don’t already know what goes where you should call an escort service from the phonebook and hire someone to show you how things work.

6. Never go to bed angry

De Angelis: I disagree. Most of us don’t do well discussing emotional topics late at night, when we’re tired and less emotionally articulate – and your well-intentioned desire to kiss and make up is likely to make him angrier. Let your partner get some rest and things will be easier to resolve in the morning.

Howard J. Markman, psychologist: Most of the relationship issues that people argue about at night can wait for another day. However, if there are urgent issues that need to be discussed, partners should talk things through earlier in the night, then try to spend what is left of the evening relaxing.

Kalish: You shouldn’t go to bed angry, but that doesn’t mean you have to solve every problem before you nod off. Even if an issue isn’t resolved, people who love each other should be able to put it aside and get some sleep, but with the understanding that it will be addressed in the near future with a time specified.

Poobomber: Well, you can go to bed mad if you want, but you’ll probably benefit from a hate-fuck first.  How can you be all that mad after a bout of sex where people’s heads are banging into walls and stuff?   Sure, you might not be in the mood for sex to begin with, but you should be aware that you might end up waking up dead with a plastic bag over your head if you don’t calm the hell down before going to the sack.

I don’t really know what I’m saying here.  Oh wait, here’s an idea – if you guys argue, maybe you shouldn’t be in a relationship?  That’s a good idea.  If you’re dating and your partner picks a fight with you, dump them.  There should be no latitude for a partner with a mind of their own.

7. Having kids will bring you closer

Schwartz: Children are an extraordinary source of joy, but they also bring conflict and difficulty into any relationship. You lose time, privacy, and intimacy. An otherwise easy relationship can be tested in a whole new way.

Kalish: The more family members you have, the more friction you have, because there are more relationship issues to work through. And if you focus exclusively on the kids, it takes away from your togetherness as a couple.

Poobomber: As long as you sell them to Chinese black market baby-traders.  The money you make can go towards a romantic vacation to Banff or the Caribbean, and we all know that fucking on a beach or a mountaintop behind some bushes is the best way to get closer to each other.

8. There is such a thing as love at first sight

Ellen Wachtel, couples therapist: False. Often it takes time for love to develop. For some people, physical chemistry plays such a big role at the outset that it is mistaken for love.

Schwartz: It’s a romantic story when it works out, but you don’t hear about the relationships that end badly. Relationships start slow and build; they aren’t necessarily wonderful from the start.

Markman: You’ll quickly know if you’re attracted to each other, but not if you’re compatible or fit to stick together through tough times.

Poobomber: What about if you’re blind?  You insensitive bitches.

9. Always keep him guessing

Behrendt: No, that’s tactical game playing, not love. It takes a lot of calculated effort and is dishonest.

Schwartz: It’s powerful and mysterious to be unpredictable, but it is also manipulative and can build resentment and anger and erode intimacy and respect.

Yagan: There’s good guessing and bad guessing, and it’s really about what kind of guessing you’re making him do. Try to keep the relationship fresh by being unexpectedly romantic.

Poobomber: The only thing a man should be guessing about is sports statistics and car engine part numbers.  If he’s wondering where the hell you were from 9pm to 2am on a Friday night, you might as well give him license to start fucking his secretary.  That’s how it works.

10. You can never be too close

Wachtel: False. Many marriages are damaged by partners thinking that closeness means not having to censor what they say or do. Some couples take each other for granted: Metaphorically speaking, they never get out of their sweat suits at home. If you don’t make an effort to be well mannered or attractive to your partner, then you’re too close.

Markman: That’s absolutely true. Closeness – emotional intimacy – is the heart of a good marriage, so it’s important to talk about what closeness means to each of you.

Poobomber: Nonsense.  Keep them at arm’s length at all times.  You don’t want them knowing about your chicken sex fantasies or seeing you cry every time you watch the Wizard of Oz.  It’s practically offering them a weakness or personality flaw for them to exploit when you’re getting divorced a few years later.

11. Love conquers all

De Angelis: Unfortunately, this is not true. Love is a big part of a lasting relationship, but shared values and commitment are still required.

Schwartz: Sadly, it’s a myth. Love won’t conquer poverty, addiction, or abuse.

Poobomber: Love can’t conquer herpes.  Nor bad acne.  Nor bullets.  Nor Genghis Khan, if he suddenly resurfaced in Mongolia and started taking over the world.  So this is stupid.

12. Everyone experiences the seven-year itch

Schwartz: The itch is true, but it doesn’t necessarily take seven years to get there. Some people get divorced within a year or less if they’re convinced the marriage isn’t salvageable.

Markman: Most partners will at some time think about divorce, but not necessarily in seven years. The data show that most people who thought about getting divorced were happy they stayed married when surveyed five years later. When things are tough, focus on increasing friendship and sensuality in the relationship.

Poobomber: Nothing a little dalliance with the mailman or your slinky second cousin at a family reunion couldn’t cure, right?

13. The way to a man’s heart is through his stomach

De Angelis: The way to a man’s heart is through his heart. Men want a woman who is going to be a great friend and companion – and if they have to order takeout, so be it!

Kuriansky: It’s true if he loves food, but that part about having to feed the needs of his heart is true, too. Still, don’t lose sight of your own needs. For a relationship to be successful, both partners need to feel pleased and fulfilled.

Gray: You’re off by about six inches. Sex is the direct way to a man’s heart.

Poobomber: Or rubbing your breasts on his face while he ‘s having supper, that’s a pretty good way to a man’s heart.  You can also try serving him hamburgers with your vagina, I don’t know how that’d work but if you can figure it out, your man will be pretty happy unless you have syphillis or something.

Really, the best way to a man’s heart is by getting some sort of forgetfulness disease and winning the lottery and turning into a red headed supermodel that can have doggy-style sex in her sleep while running a remote control with her nose.