Write the story within you. Most writers will tell you to write the book that's in you right now, the book you think about every waking minute, the book you have no choice about writing. Don't write the book your publisher wants, or the book your mother wants, or the book that's guaranteed to make the New York Times bestsellers list. If it's not the book that is kicking and screaming to get out of your head and onto paper, you'll only wind up being disappointed in it, and it probably won't please your publisher, your mother, or anyone at the New York Times. Hand in hand with that goes...
Believe in yourself. This is crucial to not only writing well, but selling the book you do write. If it's too elusive, too overwhelming, or causes you to snort derisively, please consult with a good therapist.
Keep a journal of ideas. You can keep an actual journal or book and write down story ideas, character names, plot twists, and so on. Or you can do what I do which is messier but also works: I write ideas down on slips of paper, backs of envelopes, paper napkins, or anything else I can get my hands on and then keep them all in a box that I call my Idea Box. Whenever I want an idea for a story, or I need some way to develop a plot or I need a character name, I reach into my Idea Box and pull them out. Usually one of them fits. UPDATE: I also use my iPod Touch for this, writing ideas into a memo or note and sync-ing it with my laptop. I name them all starting with "Useful Bits:" and categorize them as "Writing" so I can group them efficiently.
Don't be afraid to improve. In other words, don't expect your first writings to be perfect. They won't be. It's the nature of growing as a writer. Use each opportunity to write as a chance to develop your craft. A year from now, you'll look back on your writing and be surprised at how far you've come. That's good: it means you're growing. The scary part is when you look back at stuff you wrote years ago and it looks exactly like the stuff you wrote yesterday. That means there hasn't been enough growth. Even published writers aren't perfect writers. I was first published over twenty-five years ago and I'm still learning and growing as a writer.
Read writing books. You can find them at any local library. One of the many better ones is Writing Down the Bones by Natalie Goldberg. As a writer, you are an artist, and all artists need to learn their craft from those who have already succeeded. Books about writing will answer a lot of questions about fiction and non-fiction, synopses, characterizations, dialogue, plot, setting, description, and so forth. They are a wellspring of information, so take advantage of them.
Be a prolific reader. The more you read, the more you will see how other successful writers practice their craft, and the more you'll learn about your own.
Learn to see life from others' perspectives. Practice this in your everyday life and it will open up new worlds. Maybe you were miffed at the woman driver in the white minivan because she cut you off in the parking lot at Target and stole your space, even though you were waiting patiently with your turn signal on. But what was SHE thinking? Maybe her version went like this:
Jeez, I'm so sorry, I know you're waiting for that space, but I have to get inside and get some cough medicine for my son, who's coughing so hard, there's blood specks now. I'll be as quick as I can. I'm so sorry! I had to leave him home with his ten-year-old sister and I don't trust them home alone. Plus, the furnace repairman is coming in twenty minutes, and I can't afford another copay at the doctor's office until payday. Please forgive me for taking your space. Maybe you have a sick child at home, too. So sorry, so sorry! I'm hurrying!
Use your childhood traumas. Did you grow up in a less than idyllic setting? Many writers did. Somehow, childhood trauma and the creative arts go well together. Use it to your advantage. Parents divorced? Death in the family? Child abuse? Frequent moves and no friends? School bullies? Foster care? Family alcoholism or mental illness? If you can answer yes to any of these, first, consider therapy. Then, realize that you know firsthand what sells novels: CONFLICT. You know about betrayal and abandonment, about neglect and abuse and love as a double-edged sword. You've seen the dark side of life. Consider it research and use it in your writing. But...
Don't write your autobiography as a novel. Rarely does this work well in fiction. Creating a fictional character who shares some of the same characteristics is fine, and often successful, but make sure there's a clear boundary between that character and you.
Avoid procrastination. You can read writing books and take writing classes to improve, but you can also take it to the extreme and hinder your writing. Whether it's a fear of failure or a fear of success or just coming to the realization that learning about writing is easier than actually doing it, there comes a point where you've learned everything you need to know for now and you just need to sit down and write!
Write without editing yourself. I know this goes against what you may have learned in the classroom, but the important thing is first to get down the ideas. After you've written your first draft, then you can go back and check spelling, move words or sentences around, correct any grammatical errors, change words, cut stuff out or put new stuff in. Too often, we're trying to correct our writing before it ever makes it onto the paper, and that can stifle ideas and creativity. Instead, just write first, even if you're not sure what word to use or how to spell it. You can always mark it and check it later. Often times, I can't think of the exact word I want to use, but rather than stopping my writing and thinking about it for a long time, I'll use a >similar word< and mark it the way I just did. Then later I can go back and figure out that the word I really wanted was 'synonym.'
Learn the rules before you break them. Yes, you are occasionally allowed to break the rules in fiction. But before you begin sentences with 'but,' learn the rules. In non-fiction, journalism, and free-lance writing, good grammar is essential. In fiction, you have more leeway, but rule-breaking must always be for a good reason and not just because you can. Picture yourself with a finished manuscript, a contract with a publisher, and an editor who is a former English teacher. If you can provide a really good argument for why you broke a rule in a particular sentence or paragraph, keep it. If not, use correct grammar.
Keep on writing. Use every opportunity to write, whether it's in a class or not. Lots of people are published but that doesn't make them good writers. Good writers are hard to come by, and, in an amazing defiance of logic, they don't always get published. They're still good writers. Good writing can earn scholarships, win awards, and help you get jobs and promotions. Good writing can help you succeed at whatever you want to do, whether it's writing for a living or not. Take every chance you have to write, and see it as an investment in your future. It doesn't matter what you write about. It only matters that you keep writing.
Write through writer's block. Stuck? Unmotivated? Unfocused? Set a timer for five minutes and do a free-write. Just write about anything: classes, family, friends, your social life or lack thereof. Write about not being able to write (this is my favorite). Write about how you feel, how you want to feel, or what it feels like not to feel anything. Describe your difficulty with writing in as much detail as possible. What does it look like? How does it sound? What's the physical feeling? Write a conversation between you and your writer's block and make it serious. Humorous. Melodramatic. Hint: this technique also works for research papers and dissertations.
Endings happen. Every story needs an ending, whether you plan one or just stop writing that story one day. Planned endings are better; your readers will like you for it and will feel a sense of closure with your story. I often begin writing without an ending in mind, just letting the story take me where it will. About halfway through the story, though, I start thinking about the ending. How do I want it to end? Does the good guy win or lose? Does the nice guy finish first or last? Does my main character succeed beyond her wildest dreams, or does she fail miserably? Then I think about how to get there (to the ending) from here (where I am in the story).
I may still use some obstacles to make it hard for my protagonist to succeed, but I start working toward whatever I want my ending to be. This works whether my story is one page or one thousand pages. Then, when I have an outstanding idea of something that could happen in the story that I know will mean adding many more pages to the story or changing the ending, I have to make a decision. Sometimes I throw out my old ending and use this new idea to keep the story going. More often, however, I write the idea down and put it in my Idea Box, then keep going with the planned story. This keeps me to my page limits, and allows me to use my great idea with another story. After all, there will always be another story.