There are many techniques that you can manipulate light in a fun and artistic way:
1) Light painting, or light drawing, is a photographic technique in which exposures are made by moving a hand-held light source while taking a long exposure photograph, either to illuminate a subject or to shine a point of light directly at the camera, or by moving the camera itself during exposure, 2) Pulled focus-changing focus during the exposure. Starting completely out of focus then adjusting until it's tack sharp. The reverse can also net some great results, 3) Zoom Effect-having your subject in focus, you zoom out or in during the exposure.