Print one of each of the leaf layers in your favorite autumn color, print the trunk and then stack the layers of leaves onto the trunk from the biggest to the smallest. You can always switch out the colors of the leaves as they don't need to be glued in place.

It's quite small, so if you want it to be bigger you can size it up, just make sure to keep the proportions of the holes in the leaves and the trunk, so you can still put them on. Added a fifth layer of leaves to make a more balanced tree for scaled up versions. The fifth layer hole is to seal at the original size.