Don't bag up your fallen leaves and send them to the landfill. Dump them into a wire bin instead and let them decompose. This DIY bin is 3' tall and 4' in diameter. According to author Michelle Balz, it can hold about as many leaves as you'd stuff into nine paper bags. Once the leaves settle, you'll have more room to add more. The resulting compost is called leaf mold, and while it's not as nutrient-rich as traditional compost, it's still a valuable amendment for improving your soil and helping retain moisture.
If you're a serious composter, consider a unit with multiple bins. They're available for sale, or you can make your own from wire and wood (try re-purposing a wooden pallet). Use wire on one side to let air circulate around your scraps or clippings, and add a lid that locks or secures to keep critters out. Aim for at least two bins in your unit so you can transfer your materials from one to the other. "Stirring" the pile lets more air reach them and makes it break down faster.