I learned this technique as an actor, and it’s invaluable for bringing authenticity to your performance. So why not use it in your writing?
Characters Don’t Exist In A Void
Just as your life is a continuum from birth to death, so are your characters’ lives. And every scene you put your characters in has context in those lives. In order to bring veracity to your writing, you need to think about what your characters were doing JUST BEFORE the scene started.
Their emotional states prior to the scene will inform their actions within the scene. For instance, if a character had just been in a fist fight before a scene in an emergency room, the fallout from that fight will inform their attitudes – even their dialogue – in the emergency room scene.
Nothing happens in a vacuum.
The Moment Before May Not Be Anything You Write
That is to say, it may not be anything that appears in your novel. Unless a scene is a direct follow-on from a prior scene, your readers will most likely never see the moment before. But you will know it. And your characters will live it and react to it.
That said, sometimes it’s helpful to write out the moment before, just as in acting you and your scene partner may improv the moment before. Don’t think of it as wasted time, or wasted words, think of it as making concrete something that was abstract in your head. That’s always a worthwhile effort.
The Scene You Just Wrote Is A Moment Before Another Event
You only have so many scenes to finish your story, so pick and choose them wisely. The scene you just wrote, with its moments before for the characters, is itself a moment before the next thing to happen in your characters’ lives.
The subsequent scene may not be one you write, but it is one that will then be the moment before another scene, etc. etc. etc. Think of events in your characters’ lives as pearls on a string. Each is precious, even if you only focus on a few rare, exceptional ones. They all matter.