Painted Autumn Leaf Templates
This kit has 11 autumn leaves, drawn and painted by hand in ArtRage, then saved as layered PSDs so you can tweak colors to match your kit or change them up entirely. You can use the outline layers separately if you just want to use the line art, too. My CU terms are fairly lenient, as well–you can use them as-is or modified, just provide credit in your Credits document and don't share/sell the layered files.
While they're designed for commercial use, I painted them in realistic colors, so a quick save as PNG will let you use them to add a lovely artistic touch to your autumn layouts.