Ehem. A wise French master once told me,
"You must use your characters' weaknesses to draw in the other party. Lovers can be strong willed with plenty of personality, but intimacy can be built upon their weaknesses. When one character simply cannot go on and falls into desperation another can compliment and console them making up for their weakness. This draws people together, the support that they give each other. Their misunderstandings and resistance to intimacy is what gives rise to a dramatic romance filled with struggle."
That was my translation to English.
Now then, their exact words were,
"Sorry about that i can try but don't take me seriously because I never really had a relationship.
"
"When the MC understand his/her weakness and finding someone good enough to take care of them. The best part went i read romance is went the character fall in love not for the strengh of the other but there weakness even more went they think that it cute"
You understand! Yes! Good Yes. Good.
In theory, there are also other avenues to love other than using weakness, but they won't be warm and tender loves.
*You could have situational lovers.
These lovers have been forced together by their circumstances. Two examples I can think of are, they were engaged by their parents or they are faking a relationship for profit.
*You could have pragmatic lovers.
These lovers don't believe in any kind of emotional nature towards love. Love is mechanical and explainable, but that's fine by them. They simply have things that they obtain from each other in a mutual relationship. Examining/researching love as a science rather than an art might help you obtain much more objective knowledge on love and help you generate ideas. I will explain with examples.
Mechanically, love has nothing to do with emotions. Love is about 'time' and 'effort' given on behalf of the loved object of affection. Love is not emotional, it is about the 'consideration' given to another with their best interests in mind. Love is about trust built on clear reasons, not blind faith without rationale. To trust someone you need to understand why they act the way they do and understand why they will not betray.
*You could have perverse loves out of desire.
Alright, there are the yanderes, but what about jealousy in general? The lover could be physically attracted to their partner obsessively. Or maybe it's something that their lover has. These perverse lovers are generally a little confused, scummy, or selfish. Their loves can be one-sided.
*You could have unrequited love.
Sorta like parental love at times. This is a very sad type of love filled with heartache as only one party is in the relationship.
*You could have love out of admiration.
The lovers could be rivals or high profile individuals.
*You could have forbidden love.
*You could have lovers that cannot be together.
Romeo and Juliet.
With all of these loves you simply have to figure out a way to force contact between your characters as an author. Then you have to abuse some avenue of love to develop their feelings for each other. I personally think I will use events outside my characters control to develop romance by forcing them to interact. You can always bring characters together, but before you will get romance you need to clearly figure out what will spark their intimate connection into existence. The characters fundamentally need to have the potential to develop their romance for whatever reason. The reason why they could fall in love will likely be a major focus of your story.
Love and relationships often get messy, which makes them very interesting when people screw up and screw each other with betrayal. So your romance might not be perfect, and that makes it much better and genuine!
One person told me that romances are always unique. I would like to add to that and say that circumstances are what draw people together. From the viewpoint of the character ask yourself, "Why am I in love with XXX? How did this happen over time? There are plenty of other people that I like, find attractive, and could have developed a relationship with as an alternative to XXX. Why did these special feelings develop for only them alone?" People are complex and explaining their mental illnesses is even more complex.