Does this affect your plot down line? In certain circumstances, yes. For example:

Bruce is a studious clean-cut senior high school student. He’s portrayed as ‘geek’ for most of story, not a main character at all. Then writer decides to spruce things up and throws a dare at Bruce. Bruce accepts. He takes his friend’s ID and goes to a ‘Rave’. Big mistake, but a twist for reader. The ‘Rave’ is raided, Bruce ends up in jail because his friend is wanted by police and he’s holding fake id. He escapes and now tries to clear his name that somehow has crept into police files. A sedate YA high school book has now turned into a suspense novel all because of a character reversal.

When writing up your character(s) sketch, try to include opposite reactions, as well. By doing this, you can easily plot foreshadowing more convincingly ahead of game.

Remember that fiction is often, if not all time, crafted out of real people, real situations or real events. So think of a ‘real’ person and envision his reaction to several possible finales to a ‘dilemma’. Then start crafting ending with one of these ‘reactions’ while dropping subtle hints to a totally different ending than what your reader is expecting. Try to use this character reversal for a completely out of this world ‘awesome ending.’

Make sure your story propels forward, making your reader want to turn page. Bungee jump them out of a plane into a secret path that will drive them to finish line.

(4) And finally, THE rule. It works for narrative and it works for dialogue. Read what you've written aloud. Wherever you would pause for breath, whack in a comma. Because, you have internalized rules. You've been speaking English all your life. But as an aspiring writer, you've been so busy trying to learn "the rules" that you've forgotten rule you've known all along. And you DO know it.

If you'd like, you can look over some sentences in preceding paragraphs. You'll note some commas where they're not strictly necessary. Often, it's where I begin a sentence with a conjunction, also an alleged no-no. But that device can be used sparingly to emphasize a point. And when I do that, sometimes I whip in a comma for extra emphasis. A comma is a pause. That's what you should note if you indulge in this exercise. I'm pausing for emphasis. Read my sentences aloud. Pause at every comma. The rhythm works. It's how I talk, and you won't be all freaked out and confused as you listen because I paused in funny places.

Speaking as an editor, I run into a lot of writers who have problems with commas. Heck, speaking as someone who likes to read books and newspapers and magazines, I see commas where they shouldn't be, or missing commas where they should be. It's because we're trying to be too fancy, drifting dangerously far from "write what you know" mantra because we think we're stupid.

We're not stupid. As Sean Connery noted in FINDING FORRESTER, critics spend a day destroying what they couldn't create in a lifetime. That's also what I think of people who want us to memorize dozens of silly rules about commas. They're pauses. Nothing more, nothing less. Pause where you want to pause, not where you think someone else thinks you're supposed to pause.

Lemme remind you what writing is. Telepathy. I'm in China and you probably aren't, and you're reading this many months after I wrote it, but you know what I'm thinking. Stray commas would be a barrier to that. Good writers don't like barriers.

Just remember that a comma is a pause, and pause wherever you think you should. Blow off rules -- there are too many and they just keep changing -- and trust your gut. If you do that, I think you'll find that when you seek out publication, and find yourself working with an editor, you'll hear very little about your commas.