First find a colorful subject. Then carefully choose the time of day and point of view for photographing the scene. Ideally, you want your colorful subject to be in direct light and the water to be in complete shade. For impressionist, artistic effects, find water that’s in motion, and keep your directly lit subject off camera. Composing to exclude the object itself (and include only it’s reflection) can create some especially abstract and interesting results.
When photographing colorful reflections, bend your knees and crouch down from time to time to see if this gives you a better, more frame-filling composition. Your goal is to get as much of that reflected color as possible.
Adapted from The BetterPhoto Guide to Digital Nature Photography by Jim Miotke (AMPhoto Books, 2007, $25)