With Winter here, be sure to re fertilize all your plant after the summer growth. They will need more nutrient now, as some things are still going to flower during winter, Re-mulching is another good option.
Be sure to change your height on your mowing deck. As you will want longer grass thru winter.
Reduce your watering rate in gardens. At lease 30%.
Prune Deadwood out of trees and shrubs, This will encourage new growth in spring.
Now is also a great time to catch up on maintenance of machinery, shed equipment and gardening tools.