One way to come up with a creative writing topic is to take a small, insignificant scene from a book or movie and use that as the opening for your next writing piece. Start from there and create a whole story or poem based off that original seed. Another way to create a topic is to use junk mail. WritersDigest.com suggests using a person who is mentioned in junk mail to create a protagonist or antagonist in your story.
Think back to friends, classmates or coworkers with whom you've lost touch over the years and fashion a story around what you assume they are doing now. Take pieces from their past when you knew them and create a fantastic or even a morbid future for them.
Listen to conversations between the people around you while you are standing in line at the grocery store, sitting on the train or eating at a restaurant. Take a small part from what they are speaking about and create a story around that.
Young children often make up elaborate stories, so use one of theirs to jump-start an idea for your next piece. Take the plot, one of the characters or the setting and make up something magical.