For this exercise you need a dark room, a flashlight, a reflective surface like a CD, a black sheet of paper and of course your camera on a tripod. Create some droplets on the CD and photograph them in darkness while using a small flash light to illuminate the droplets. I used different exposure times ranking from 6 seconds to 30 seconds, a 100 ISO setting and an aperture setting from f8 – f32 on my 180mm macro lens. You most likely have to experiment with these settings.
This is my second image, the first one was too dark. I uses an aperture setting of f22, ISO 100 and 30 seconds exposure time. My flashlight was also mostly covered up.
Enjoy and keep on experimenting!