We love the look of pine cones and acorns on a fall table. To kill any insects hiding inside, first spread your collection of cones and acorns (not leaves!) on a cookie sheet and bake at 175 degrees for 1-1/2 to 2 hours with the door ajar. Check every 15 minutes to avoid scorching. After the cones and acorns cool, you can confidently place them on your table without worrying about unwanted “guests” making an appearance on your tablecloth. This process makes them safe for craft use too.