I like this idea...Sort out the nicest of the bunch. Make sure they are all dry.Now melt some beeswax in a double-boiler. I just melted down a bunch of old candle stubs. If I'd had it on hand, I would have added a drop or two of cinnamon oil.When it is thoroughly melted, take the leaves by the stem and immerse them, one at a time, in the wax. Hold them over the pot to drip a bit, then lay them on waxed paper. Continue until you have a nice assortment.
Find a paper napkin with fall leaves or other fall motifs and decoupage them onto the stones. It is so easy and the result looks great. Light colored stones are perfect for this project, but you can also paint darker stones white if you like.