Ten Things You Can Do to Jump Start Your Writing Life
Color Spark: Put together a palette of colors (DeGraeve's Palette Generator will make one for you based on any online pic you feed to it) and create a character or setting based on the color combination.
Copy That: Write cover copy for a short story or novel you want to write. If you like how it comes out, use the copy as your story outline.
Cover It: Create a book cover for a story you want to write, and hang it up in your writing space as inspiration/motivation. Or use a cover generator like this French one (input your byline in the box and pick an edition) to generate something random, and write a story based on your results.
Descriptive: Go to a beautiful spot with a notebook, pen and (optional) camera. Describe where you are and what you see in as much detail as you can in your notebook. If you bring a camera, take photos of the most interesting aspects of your spot. You now have the setting for a scene; when you get home write one.
Eavesdrop: The next time you go out (and make sure you do this discreetly/safely) take a notepad and jot down the most interesting things you hear the people around you say. When you get home, choose one or more of the things you wrote down as dialogue, and write them into a scene.
Hour Aside: Devote one hour at the same time every day to work on a writing project (or, if you don't have one, start a new project.) People with day jobs, try getting up an hour earlier -- that always works for me.
Idea Book/Journal: Start a journal of writing ideas. You can just list whatever comes to mind when you think about writing. If you already have enough story ideas, write a journal from the POV of a character.
Super Short: Write a flash fiction of 100 words or less. If you want a real challenge, write a one-sentence story.
Trunk Treasures: Unearth any old story you never finished. Take from it one element (character, dialogue, plot, setting) and use that as inspiration for a new short story.
Uncontest: Find a fee-free writing contest that intrigues you, and write a submission for that contest just for fun (note: if you finish the story in time for the contest's deadline, submitting it would be awesome.)