Back To The Future (1985)
The Girl: Lorraine Baines (Lea Thompson)
The Geek: George McFly (Crispin Glover)
The Technique: This one is pretty much reliant on destiny - or your child arriving from the future in a converted DeLorean time machine. So don't go pinning your hopes on it.
But while Marty's interference does have a big impact on George McFly's interaction with Lorraine, it's him overcoming his confidence issues and standing up to bully Biff (Thomas F Wilson).
Believe in yourself - and you'll win the day.