You know all about "boy meets girl" - it's one of the most common things we see in stories, even ones that don't have romance as their primary reason for being. But if you're working in a world with alternate social rules, one thing you should probably consider is how boys and girls meet each other. After all, if they aren't meeting each other at all, then that makes it hard for them to fall in love. And if they are meeting each other in very restricted circumstances, that may have a deep influence on what the society considers relevant to choosing a match.
Imagine the situation where boys and girls aren't allowed to meet. The sexes are totally separated as much as possible, so love between a potential husband and wife is probably not considered that important. This is the kind of place where you'd expect to see arranged matches based on criteria that can be assessed within the isolated context.
Imagine the situation where boys and girls play together all the time, but boys and girls tend to be separated for things like team activities, and gender roles are seen to be relatively distinct. Relationships form, and some boys understand girls better because they have sisters or cousins who force the gender-divided expectations to be broken down, and vice versa for girls understanding boys. But there are also going to be large groups of boys who haven't had much contact with girls and know their ways mostly by hearsay and culturally based report. This is sort of the situation my children are currently working in.
Every parameter you change is going to have a huge influence on how relationships form.
In this vein, I was thinking about Disney princesses. We watched Mulan a couple of days ago. I remarked to my daughter how this was my favorite of the Disney princess movies, and she said, "but she's not a princess." It was a good observation. Mulan is obviously a member of a noble family, but really, she's not a princess. And I think the reason why I always enjoyed her relationship with the Captain was that in spite of the deception involved in her pretending to be male, she actually got to know him. They went through rough things together. Compare that with the typical love-at-first-sight scenario that we see basically everywhere else in the Disney princess canon.
If you think about it, the idea of love at first sight in itself isn't a horrible thing - instant attractions happen. But when you look structurally at the positions the princesses are put in, they aren't ever in positions where meeting a boy will happen naturally and allow them to get to know each other. Historical princesses had some of this difficulty as well (though I imagine they were more realistic in their personalities), because the ways in which they were allowed to interact with potential matches were very circumscribed. If you're only ever going to be meeting any member of the opposite sex for an hour at a time, on a dance floor, then NOT believing in love at first sight is going to be a problem, because it will simply mean you have to resign yourself to not loving the person you're going to marry. Which of course does happen, but we like to think of these matches in an idealized way (because thinking of them any other way might be depressing! Just witness the Disney princess annotated portrait that has been floating around the internet lately).
Now, an example from my Varin world. The social parameters in Varin are twisted by the fact that the noble caste is in decline and in desperate need of healthy children (which it finds difficult to procure). As a result of this, women in the noble caste (but not the ones below) are very oppressed, and rushed into babymaking as soon as possible (age 17, which in the global scheme of things is not horrible, but still very early from my own point of view). Because their health and safety is considered a priority, the Grobal women are given bodyguard-nurses at birth, and these companions safeguard them until they are grown. This means that it is extremely difficult for boys to interact with girls. Boys are expected to approach the girl's servant before they approach the girl herself, to the extent that they must speak with the servant first until they get permission to speak to the girl. This means that boys without sisters have very little idea how to interact with girls at all. It also means that arranged marriages are the norm. Arranged marriages are also the norm because of the need for alliances between the Great Families, and they are typically arranged by men in power, so you end up with lots of couples where the man is 20 years older than the woman - because the man is powerful enough to make the arrangement successfully, and the woman is being rushed into childbearing. This has consequences all through the society because love is not generally the currency on which these things are based, and because young people are not able to satisfy their sexual appetites without braving bodyguards and serious trouble (which means they look for various other ways to satisfy them that I won't go into here).
What parameters for interaction have you set up in your world? How do boys and girls meet? What are the expectations for love and marriage? How does that change expectations and behavior?
It's something to think about.