You know, it's hilarious that I'm sitting down to write this blog post, for many of my pieces of advice are things that I have never been able to do...
1. A Tale is Born
The step of choosing a storyline always seems to come like a bolt from the blue (pardon my cliche). For those enterprising authors out there, carry a notebook, preferably a Mead Composition Book. You never know where or when an idea might hit you. (I've had inspiration come from everywhere: Chinese class, History reading, riding on a subway, playing the piano, Biology class...)
Another thing is, don't feel pressed to finish your whole storyline right now. Just get the basic conflict and resolution, as well as any plot twists. The different "mini-plots," as I like to think of them, can wait.
2. Your World
The setting and the character are intricately interwoven, whichever one you choose first influencing your choice of the second one. However, it is much easier to fit a character to a setting than to fit a setting to a character. There are, however, some instances of fitting a setting to a character, such as A Connecticut Yankee in King Arthur's Court by Mark Twain. The resulting stories are usually mildly absurd, no matter how serious the storyline.
3. The Traveler Awakes
Your character, much like your storyline, can come at anytime. It can be based on anything from the criminal on trial, to the homeless man standing on the corner, to the police officer who gives you or your acquaintance a ticket .
Needless to say, your character will be infinitely important to your storyline, so don't be afraid to put some time and energy into making this: the star of your show.
Your character, whom you may or may not like, will be constantly evolving. You put him in a situation and hey presto! he's further defined. How you or I cope with a problem will change who we are. These experiences will influence our future decisions. The same is true for characters. Be careful how you write a scene, or your character may end up a stranger to you.
4. A Family Tree
You have your character, but who does your character have? He can't see his future and the friends he will make. Right now, he's all alone in a wilderness of words. That, my dear friend, is where you and I come in. Populate your story! Feel free to explore and expound.
The most basic piece of your puzzle is your character's family. Who are his parents? Does he have siblings? If so, what are their relationships? What about cousins, aunts, uncles, grandparents, nephews, nieces, grandchildren...?
Don't worry. This is a piece that can be put in at any time, and you don't have to do it now. However, the more trailblazing you do, the more shaped will be your pieces, and you may end up having to do something with your character's family that you would rather not do.
5. Geography, Anyone?
Welcome, friends, to the closest thing to being a deity. In your world, you have absolute power to do anything you wish. Want to have an enormous mountain range between two countries that can't be crossed except through goblin-infested mines? Go ahead. (Although that is plagiarizing, which is illegal...)
The most important part of geography is the landscape (of course). Is your world land-bound? Is it an island? Any mountains your adventurers should be aware of? Don't forget the swamps. Where are those? The possibilities are bound only by your imagination.
6. The Masses
Who is your world populated with? Humans? Talking animals? Fantastic creatures? Where do these beings live? What are their agendas?
The unnamed, faceless, countless creatures with which your world is populated are among the most important ingredients in your story. From these, you can pluck a new hero, who will then be catapulted to glory (or failure). These can also spawn a new villain with which you can terrorize your protagonists.
The masses also provide useful side characters. With the millions and millions of people in your story, your options are endless. You are a great spider, weaving a web of intrigue and terror, or, if that's not your thing, love and romance. The masses can be the dwelling place of strange beasts or jealous suitors: whatever suits your whim or need.
7. Evil Rises
You have a happy, safe protagonist (although, depending on who or what your masses are, possibly not so safe) with a happy, loving family (I hope not). You have no purpose to your story. What now? What could possibly disrupt your character's life for all time?
You understand! I can imagine the light in your eyes as you realize that, as in all good 'Adventure Fiction,' your tale needs an antagonist. Will it be the protagonist's family member, as in Star Wars and Eldest? Will it be an ancient menace, as in The Lord of the Rings? Or will it be an unknown but deadly figure, rising from the masses to take possession of his namesake?
The choice, as always, is yours.
8. A Quest Begins
Welcome to the last stage of development. You have a protagonist. You have an antagonist. You now need a purpose. Is it a race to recover a lost artifact? Is it a country bumpkin attempting to destroy an evil dictator? Well? It is your choice.
9. Continue Exploring!
You've begun your tale. You have a purpose. You can now write! Let inspiration move your fingers as you explore and discover your world, refining and clarifying many facets that you could not have suspected existed even hours ago.
Finally, have fun!