Autumn fishing is the last and probably the beautiful part from fishing season. Dry fly fishing is very nice and productive. Fishing with nymphs is more difficult and demanding due to low and very clear water. Based on years and years of fishing I consider this period of time the most beautiful for fishing with nymphs.
I noticed that fish are pick the nymphs with higher attention and is not easy at all to fool them. Small, dark colored nymphs brown, dark grey, dark olive with a little bit of purple, blue or violet are the best for Autumn time.
Here are a few from what I use: