There are 3 main theories to writing a story... Tunneling it, Mapping it or Basing it. Let's discuss.
I'm probably using the completely wrong words to describe these 3 writing philosophies, but that's ok... you'll get the point. What is Tunneling? What is Mapping? What is Basing?
Tunneling is when you figure out a basic story, start from the beginning and just continue writing from beginning to end. Mapping is when you figure out a basic story, then look at it from a higher perspective to figure out what you want to happen, i.e. scenes, dialogues, climax, etc. Basing it, is when you base your story loosely or closely to a real-life event.
The fun part of tunneling is you get to live the story as you're writing it. You start from the beginning point, and keep moving the story along, living from within the world of the story. For example, a guy gets his bike stolen and he really needs his bike to provide for his family. After the bike is stolen, what does he do? He goes to the police. They can't help him so he decides to handle it himself. He runs around the city and finds a clue. He does this, he does that, and eventually you walk yourself through the whole story until it ends. One of the most important things about tunneling is that you MUST start with a thesis in mind. WHY are you telling this story? What are some themes you want to get across? Ask yourself a few fundamental questions of why you're writing the story, and it will help the entire story make sense.
Mapping is a bit more complicated. It's literally like... mapping. If you’re to build a city, you have to figure out where to place all the parts and how each part will fit with the other. The neighborhood here, the parks here, the sewer system there, etc. etc. First you start with a basic story concept and themes/thesis, like last time... then you look at the story from above and figure out what can happen in this story that is fascinating. What scenes would be interesting? What characters are necessary to tell the story? What obstacles are needed to make the story worthwhile? Etc., etc... Slowly putting together pieces of the puzzle, reworking it over and over can be difficult, but will also create a very wonderfully complex world.
Basing is when you base your story on something that happened in real life. You find an event that happened, figure out why it was important... then start working out where to start, where to end and why you want to tell this story. You have to teeter on a line between what is interesting and what is true. If you can find an interesting enough story, it then just becomes about figuring out how to piece it together so that it feels as interesting as a regular story.
Everyone has their own style of writing. Some styles come easier to some people and others to others. Once you figure out how you want to write your story, run with it! :)