How to kick start your choppin imagination...
Flip the image 90degrees one way or another... even 180 and see if you can see something else in the image. Duplicate the image, perhaps by mirroring it you will see something new.
Think of the main item in the image being somewhere else.. Maybe think of it as a different size. Such as a little box on a table, might become a big box on a street and now you can make it a building. A tiny styrofoam cube becomes a cozy igloo home.
http://photoshopcontest.com/view-entry/130354/unexpected-dinner-guests.html
A little pile of sand in the street can become a big pile of sand on the beach.
http://photoshopcontest.com/view-entry/128361/sunburn.html
Inanimate ojects can be animated, by adding limbs and facial expressions, and proper shadows and textures and if you can make it a gif. Something flat can be given a different shape and depth.
http://photoshopcontest.com/view-entry/119874/mr-cabbage.html
A texture in the image might give you an idea or remind you of something else. The shape might be used as something else. Take it apart and see what you can make out of it, either in your mind, on a piece of paper or actually take it apart in photoshop... and remember a round object can become some other shape. A wall could be a floor. A tunnel can become a well. A plant could become abstract hair, a torchlight or a very scary fish!
http://photoshopcontest.com/view-entry/127796/kohltiti.html
http://photoshopcontest.com/view-entry/167614/torchlight-discovery.html
http://photoshopcontest.com/view-entry/135143/piranha-rose.html
a flower could be a dress, or a favorite treat, a bird, a fish -- check out the entries on this contest of a unusual bright colored flower...
http://photoshopcontest.com/photoshop-contest/2231/purple-flower.html?l=&o=votes
Color, lighting, depth, mood. Try different coloring or adding illumination. make another layer over the image and try out different brushes. Add other elements. Add mood or humor. Adding a clever title or explanation is good too.
http://photoshopcontest.com/view-entry/113739/wee-fountain.html
http://photoshopcontest.com/view-entry/98007/robocar.html
Reshape. Turn your brain inside out... something like a sphere could become something flat. something empty could be full. something right side up could be turned upside down. something shut could be open. something bright and shiny new can become some dark rusty thing. something ordinary can become bizarre.
take a look at these three... same original image. three very different results.
http://photoshopcontest.com/view-entry/123732/votes.html
http://photoshopcontest.com/view-entry/122539/introverted-extrovert.html
http://photoshopcontest.com/view-entry/123954/votes.html
Study other entries for ideas. take a look at the contest gallery links (bottom left). look at portfolios. compare the original to the entries.