(Click pic for larger)
It’s important to pay attention to the color of your ambient light. I took this at 06:38 Sunday morning, the sun coming up over my left shoulder through a thin overcast. Using a polarizing filter allowed me to darken the sky in front of me, while biasing the white balance towards tungsten allowed me to get the hostas in the foreground (lit by the lamppost next to me) to turn white, while giving me that delicious blue sky and reflection.
The polarizer also acted as a neutral-density filter- stretching the exposure out to 10 seconds at f/9.5 – which gave me time to add just a little more light to the hostas with a flashlight. I always carry a powerful flashlight or two with me when shooting for just this reason.