Meet Quirky Heroine. She is (hopelessly single/recently divorced/dating Hunky Loser).
Enter Mysterious Hero. He is (apparently a total jerk/too good to be true). Heroine and Hero dislike one another because of Coincidental Misunderstanding and part ways.
In Random Twist of Fate, Quirky and Mysterious meet up again. They are forced to (collaborate in a project/live in close proximity), and they begin to warm up to one another. They both (tell white lies/omit certain truths) so the (Quirkiness/Mystery) (doesn't seem so bad/is endearing). They hook up.
After Montage of Fun and Chemistry, Quirkiness begins to irritate and dreadful Mystery is revealed. Angry accusations communicate betrayal of trust and nasty breakup ensues.
Loneliness Montage shows Hero (toying with relic of Quirkiness/struggling to concentrate on previously-shared project) and Heroine moving on with Mundane Life, occasionally wiping away tears. Background Music communicates hurtful potential of misunderstood love.
Hero begins working on Vast Project, details of which are obscured. Soundtrack hushes as he shows up on Heroine's doorstep with penitent apology and (is rejected/meets new boyfriend, Hunky Loser). He (leaves a standing invitation for Heroine to come to Project location/colludes with Heroine’s Comedic Best Friend to erect Project in Easily Discoverable Place).
Heroine (stumbles upon/, denying her curiosity, finds) Project, which is Fulfillment of her Wildest Dreams, and realizes own selfishness. Hero, however, is already on way to drown sorrows in Remote Place for Extended Period of time. Heroine humiliates self in mad rush to airport/dock/station.
Hero (hasn't quite left yet/changed mind at the last minute). Heroine catches Hero and breathlessly communicates Change of Heart. Lengthy kiss during Drastic Zoomout out indicates reconciliation of Quirkiness and Mystery.
(Soft rock/Classic) crooner sings beaming women and blinking boyfriends back into brightly lit, popcorn-strewn lobby.
Works every time.