Gather decorative leaves for your stepping stones. Decide how many leaves you'd like per stone and collect that many leaves for each stepping stone you plan to make. Collect a few extras, just in case.
Prepare your work surface. Work outside or in a well ventilated area. Lay down a drop cloth or newspaper to protect your floors and table. Understand that resin is very difficult to remove if it gets on your home's surfaces where it's not welcome.
Mix your craft resin in a disposable container with a disposable stick. The resin can't be later removed, so be sure you don't use anything valuable. After you add the catalyst to the resin, stir immediately. Mix only enough resin to make one stone at a time because the resin will start to set after about 20 minutes.
Lay your round, rubber stepping stone mold on your work surface. Make sure the mold is completely flat and able to stay in one place without being disturbed as the resin sets. If you cannot find a resin mold, you can use a shallow silicone pie pan.
Pour a half inch of resin into the mold. Press one or more leaves into the resin, flattening out any air bubbles with your fingers, but not pressing the leaves deep into the resin. Pour another half inch of resin and press more leaves if you like. Continue this process until you have filled the mold to the top.
Let the resin cure overnight. When the resin is set and completely hardened, carefully work it out of the mold. Use an emery cloth to smooth any imperfections on the surface of the resin. Allow the stone to cure for another 28 hours before placing on your lawn to be sure it reaches maximum hardness. This will prevent debris from becoming embedded in it before hardening. Repeat for additional stones until you've made enough for an attractive walkway.