The best way to start a novel, or for that matter, a two-page long short story, is with six paragraphs of exposition and setting establishing. Hey, writers were doing it all the time hundreds of years ago! And in literature, EVERYTHING old is good, without exception!
If you have a character express an opinion about some social issue, it MUST be the same as your opinion about it! After all, if you have the character say THEY believe something, your readers will assume that YOU believe that same thing, because a writer would never make up stuff that doesn't apply to their own lives.
Alternatively, you can have the villain, or some unpleasant, incidental character express an opinion that is the exact opposite of what you believe, just as long as it's exaggerated to the extreme. For example, don't have someone support an act of warfare because they think it will ultimately lead to a safer world. Have them support it because they love violent wars and want the poor to die fighting them and also they eat babies.
If you write horror, don't bother setting up a genuinely scary atmosphere, just have your character think that it's scary. Maybe have them say something like, "I'd never felt this scared before in my life" because that subtly communicates that the place they're in is scary.
Write a short story that has no purpose except to "surprise" the reader with a twist ending. If you write scifi, make sure that twist ending is where you thought you were on an alien planet but you were on Earth, or vice-versa. Also, steal from the Twilight Zone.
Also regarding the twist ending: if you write horror, remember that no one reading your story will have ever read a horror story in their lives, or watched a horror movie, or gone outside on Halloween. So when one of your characters only shows up at night, never eats, and looks pale all the time, the reader will be incredibly surprised when you reveal he's a vampire.
Remember, every genre has magical eraser phases that keep you from having to justify what happened!
For fantasy- Magic did it!
For scifi- It was a space-time anomaly! OR It was a technological breakthrough!
For horror- It's inexplicable! Oooh spooky! (Bonus points if you also say "supernatural." wink
They're great! Use them as often as possible!