The internet is a source of the most amazing and extraordinary images, many of which simply cry out to be used as starting points for short stories. For example, if you see this photo (see below) it has to make your mind begin to wander around all manner of possible stories.
What on earth is happening in this photo? Why is that nonchalant young woman sitting on her bed apparently being embraced by a large and peaceful bear? Is the bear comforting her? Why is she apparently ignoring the bear? What on earth is she doing, dressed only in her nightgown, with a large and amiable bear beside her?
As you can see, such an image could surely be used by your students (or yourself) as the starting point (or equally, the end point) of a short story of just about any genre.
I have long been fond of using such images to get my writing juices flowing, and the advent of the internet has been a real boon to individuals such as I in this respect. So much easier than having to go to a library and ploughing through volumes of stuff to find that one exciting image that I need to get me going.