Every year, when the trees are finished using their leaves, they throw piles of them onto the grass in our garden, I like to pick some of them up and use them again!
This year I made some goodies for friends.
I cut heart shapes out of the leaves, before pressing them under a pile of books.
In this memento, I layered 3 pressed leaves, with a heart shape cut out of the top one only, and the rich rust-red leaf in the middle showing through.  I used a little wood glue to keep everything together and tied it with a ribbon.  
I attached a handwritten tag and gave it to a friend for her birthday.  She invited us to breakfast, and specifically asked for no gifts, just a message from each of us.

Autumn is a second Spring, when every leaf is a flower – Albert Camus