This type of abstract macro has been floating around in my head for a while but I just now got around to getting it out from between my ears and into the camera. The setup: Take a small glass bowl and fill it with water. Add dishwashing soap and food coloring (I used a neon blue). Place a flash configured for slave mode on the table next to the bowl with the flash head pointed at a 45 to 90 degree angle with respect to where you’ll be photographing (you don’t want the flash pointing toward you or directly away from you due to some possibly bad reflections from the flash). Then use a drinking straw to blow air into the water to make the bubbles.
I used an MR-14EX set as a master (the 430EX on the table ended up being a “C” channel flash) and an MPE-65mm macro lens set to around 3x to emphasize the gaps between the bubbles. Then I went looking for interesting compositions and lines in the mass of soap bubbles, often shooting well into the pile. Using the 430EX to pump light into the bowl really brought out the surface of the bubbles and where they intersected with each other.