Leaves must be completely dry. Melt beeswax in a double-boiler. Can use old candle stubs. (Optional - add a few drops of cinnamon oil). Hold leaves by the stem and dip in wax. Let excess drip off, then lay them on waxed paper to dry.
Leaves dipped in wax to preserve color. I would like this hanging over my kitchen window this fall. -- beautiful idea for a mobile or general hanging decoration, would be better with resin than wax IMO