A fistful of autumn leaves.
A needle and a little bit of thread.
A simple garland that doesn't cost anything and feels festive without being silly.
I sorted the leaves into color piles and then played around with laying them out for a gradated look, but you could do alternating colors or anything else you can think of. My only tip is to work with the leaves as soon as you collect them. String them gently (a few will rip) and then get it hung before the leaves dry out. They are harder to work with once dried.