There's a fun little practice that I learned about through Waldorf education and The Creative Family: keeping a seasonal nature table specifically for young children. It makes me more aware of the changing cycle of the year and allows my daughter to participate in those cycles by having a place to display her treasures.
Our fall-time nature shelves are pack with goodies. I think my favorite moments this autumn have been when she finds a pretty leaf and says, "This goes on my nature shelf!" Part of the change happening outside then comes inside and becomes a part of us.
Nature Table pool on Flickr has some incredible photos & crafts.
This book has fun ideas: