Fall watering gives plants a reserve for winter, especially evergreens. Soil should be kept moist but not soggy until the ground freezes.
Be sure to Spray Boxwood and Dwarf Alberta Spruce with Neem oil to control spider mites.
For winter protection, wait until consistently freezing temperatures and plants are dormant. Construct a burlap fence around young evergreens such as boxwoods and arborvitae. Protect young, small deciduous trees and shrubs with sensitive flower buds with a tomato cage or cylinder of snow fencing packed with leaves or straw.
Wrap trunks of young trees, less than 5 years old, to prevent frost cracks and animal damage. Be sure to remove any protection, you applied for winter, in the early spring.
Pruning, only prune plants that have disease issues. Dispose of any diseased leaves and pruned material so it is not there to reinfect the plant the following year. If no issues are present it is best to wait until spring to prune. Pruning can encourage new growth that will not have time to harden off before winter.
See attached video for winter protection of Big leaf Hydrangeas to increase blooming for the following year.