Ideas are the easy part. We all have ideas. They might be ideas for a book, a commercial, a song, a painting, or a better way to slice cheese. Ideas are the easy part.
Execution is the hard part.
I've talked in past blog posts about a time in my recent past when I had lost the ability to write and how hard I worked to get it back. I won't bore you with that if you've already read it, and if you haven't, I invite you to poke around this blog a bit until you find it.
Now I find I can execute the ideas--put them on the page in paragraphs and dialog, description and mood, reflection and protection--with ease, most of the time. When I have difficulty, I just start posting things on Facebook, or temper myself with the Tweet limit of 140 characters.
Sometimes it comes easily and I give credit to a fictional character I created, an affectation I call Ralph, the Muse. Good old Ralph, though he doesn't exist, wears a long, stained, once-white toga like bed sheet, has tangles in his beard full of bread crumbs and lost forks, and smells pretty bad. Sometimes it comes like an eight-grader trying to write a 500 word report on Robert Frost's poem about taking one path or the other through the woods when it's plain he would rather be inside watching cartoons (Frost, and the eighth-grader.)
Here's a tip for someone who wants or has to write, but can't get started:
Write something. Anything. Just get the juices flowing. Be prepared to delete or otherwise obliterate what you write. Or post a Facebook update about something ridiculous (especially if you need to keep your eye on word count), and then delete it or show some cajones and post it.
I think you'll find that getting the motor started is the hard part, and that once your brain is used to stringing words together it's pretty easy to continue.
Go for it. Stop reading now. Write something.