The typical blue or yellow/green sponges are made from plastic. The little pieces that come off during use, go down the drain, and can end up in the ocean. Switch to plant based sponges like the ones by Twist, and scouring pads made from walnut from Full Circle. Both are biodegradable.
Ditch your dish soap. Typical antibacterial dish soaps contains ingredients like triclosan (read more about it here) that are harmful to the health of people as well as the environment. Try a dish soap that says it's 100% biodegradable or use a bar of castile soap. Simply run your damp sponge over it to get great dish cleaning suds.
Go for uncoated cardboard rounds. The grease-proof coating is made from plastic and makes them not biodegradable.
Make your own earth friendly countertop spray. Fill an old spray bottle with with 50% water, 50% white vinegar, and 20 drops of essential oil. Use orange essential oil for cutting through the grease left on your countertops from buttercream. Shake before use.
Switch to unbleached parchment paper.
Don't trash your scraps! Food waste emits greenhouse gasses. Give your cut offs and extra fillings new life as mini cakes, cake pops, or just share with your family. Find second uses for other kitchen scraps. For example, save your veggie cut offs in the freezer and then pop in a crock pot with water to make veggie broth once a month.