Take any object or scene and make it appear sinister. The best images
will make the viewer feel a little uneasy, maybe not instantly but
after studying the scene for a few seconds and understanding its
ramifications. More points to those who can do this to an everyday or
household object, or who can somehow portray a scene from a bigger
story - a sinister event or situation. Photoshop enhancements are okay
as long as they imitate traditional darkroom techniques or a certain
film stock / processing trick.
Some ideas: Consider lighting, high contrast film, IR film, grain,
black & white, makeup, Solarization (Sabatier Effect), fake blood and
multiple exposures.
Think: Hollywood horror, flashlight camping faces, mist or fog, dead
things, storm-clouds, fire damage, long shadows, Salem witch trials,
Hillary Clinton, moonlit scenes, monsters under the bed, deadly
weapons, Gothics, Gargoyles and spooky music.