Melted crayon art is an easy and fun thing. Peoples of all ages can create different types of such crafts using different methods. The finished products can make great gifts or party favors.
Last of the Autumn Leaves: Leaf mobiles/sun catchers (project page also shows some awesome suncatchers) This is just the idea I had.
8 Gorgeous Fall Crafts on It’s Playtime! Love that puzzle piece tree!
Leaf activities: Leaf crafts: 14 fall leaf crafts for kids.
Creative crafts for kids of all ages: Leaf printing. Just paint on a rainbow design of a tree on a leaf and use as a stamp.
Train tracks, blocks, marbles = awesome run marbles down the groves in the track
How to Build a Paper Plate Spiral Marble Track - The marbles spin around and around down to the bottom!
Learning Colors Through Nature - Fireflies and Mud Pies