~Check online foliage reports to find peak foliage in your area so you'll know just where to go to find the strongest areas of color.
~Plan on shooting early in the morning or late in the afternoon for warmer lighting, you'll want to avoid the contrast of harsh mid-day light. I prefer to shoot early in the morning to catch any early morning mist which adds mood, and dew can add detail to any macro images you shoot. In late Autumn, early morning also brings the chance of frost, sometimes even snow here in Maine!
~Blue skies are a beautiful contrast to warm foliage colors. Thing about using your polarizer to reduce glare and deepen colors. Polarizers are also great for shooting wet leaves.
~Overcast lighting will saturate colors and make them pop, and it eliminates highlights and harsh shadows. Just don't include any empty white sky in your composition.
~Foggy days can really add mood to your foliage photos.
~Look for contrasts in color such as one branch of brightly colored leaves against an evergreen background, one colorful leaf surrounded by others which haven't turned yet, small amounts of color remaining where all else has gone brown... really look for interesting color combinations and contrasts.
~Look for colorful reflections, the leaves don't always need to be the main subject.
~On a windy day, try using a slow shutter speed on moving leaves for a more Impressionistic photo.
You can also move your camera with that slow shutter speed to create an abstract image.
~Try shooting backlit leaves to bring out the veining detail.
Enjoy this very special time of year!