Walk For Inspiration
Go for a walk and make a note (possibly just a mental one) of things in odd places, for example unusual items discarded on the pavement. Use the items in a story or write one explaining how they all got there.
Be Artful
Visit an art gallery (or an online gallery if you can't get to one) and look at any pictures showing a group of people. Don't read the descriptions, make up your own story about who they are and what's happening. (Magazine adverts can also be used for this exercise.)
Change the Scenery
Find a new place to write. Cafes and other public places are particularly good when you're feeling isolated and/or sulky. This can help you past a tough spot in an ongoing piece, or use your surroundings to inspire you to write a new one.
Picture Seeds
Use any or all of the pictures below for a starting point and write for fifteen minutes.