A few readers have asked me to put all of these "truism" posts, scattered over the past 18 months, in one convenient place for persual. So be it (just click on the numbers to get to the corresponding links).
# 1: The primary challenge lies not in creating obstacles to keep the couple apart, but in convincing the audience that these two people truly do belong together.
# 2: A star can open a romantic comedy, but a protagonist who doesn't make sense will piss off the movie's audience forever.
#3: The depth of your audience's emotional investment in the central romance is directly proportionate to the size of the story's stakes.
#4: Solve the Woman Problem and you will get rich.
#5: The most effective function of a subplot is to show how the protoganist is transformed by love.
#6: Formulaic approaches to this genre have become so self-parodying that a fresh and imaginative take on your story is mandatory.
#7: To humiliate one of your protagonists is wonderful, but to humiliate both is divine.
#8: A theme that resonates with your audience can excuse a multitude of contrivances.
#9: The less said, the more felt.
#10: A cliché is as good as you can make it new.
Doubtless there are other romantic comedy truisms to be explored in the future, but let's call this an initial "top ten."
Enjoy, learn, and prosper.