Work underwater. Fill up a large bowl, vase, or old fish tank with water and create something inside of it.
Problem: I do not own anything resembling a large bowl, vase or old fish tank. In fact, the largest clear container i could dig up is... a pint glass. Hmmm.
While scrounging around for some plastic, i came across a work manual that had a clear plastic cover. *lightbulb moment!* The cover promptly got cut up into strips, the Sharpies came out, water was added to the glass and the now-coloured plastic strip inserted into it. Position everything in front of a white background... aaaand... done!