8. Weed one last time.
Do a thorough weeding of your perennial beds now and don't forget your other beds too. You may be surprised at how weeds can take over during the cool weather of fall and early spring when perennials are dormant. A friend of mine was very surprised to see the grass seed sprouting that he had planted thinking he wouldn't see it before spring. Then apply a 2- or 3-inch layer of bark mulch or pine straw over the beds. Apply fresh mulch around trees, too. Remove and compost some of the old mulch, if necessary, to keep the mulch layer just a few inches deep. Any deeper than a couple inches and it can suffocate roots. Placing landscape fabric beneath mulch helps control weeds while allowing air and water to reach the soil.
9. Gather fallen leaves.
You can leave a light scattering of leaves on the lawn and mow over them to add organic matter and nutrients. However, you'll want to use a sturdy rake to gather and compost a thick layer; otherwise, the leaves can smother the grass and some kinds of leaves leave tanic acid that can completely kill your grass and change the chemical make up of your soil so that only moss will grow. Whatever you do, don't throw them away! Add them to your compost pile or simply pile them up in a corner or if you live near a wooded area just put your leaves into the wooded area to decompose. They'll decompose into "fertilizer" rich in nutrients and organic matter, which you can spread in beds next spring and mix in with your soil.
Remember anything you do to improve your landscaping and flower beds in the fall will benefit you in the spring months and reduce the effort you need to put in so that you can prepare your home to sell in the spring market. Curb appeal goes a long way to getting people in the front door. Don't forget to take seasonal pictures of your home for your album too. Prospective home buyers like to see pictures of homes in different season, it helps them make a decision.