These are my main tips for writing:
*Make sure you have something to write about, make sure you write about something you're really sure of, not just what you kind of think is important to write about.
*Write to make yourself happy.
*Really want to write, don't write because you think you should be writing, if you really want to start writing a story but can't seem to be able to just sit down with a pad of paper and write what ever comes to you! If that doesn't work why don't you try and decide a storyline, work out who the characters will be and then start writing.
*Make sure you believe you can write a great story, if someone tells you that it's stupid to be writing a story don't take any notice of them, always believe in yourself.
If anyone would like to ask something about writing your story, just comment! I'd love to hear any story ideas, it'd make my day!
Keep writing and I hope this has helped you start to write your own story!