Still, in a quick and easy green gardening world, it is possible to develop a system that is eighty percent nature and twenty percent gardener. Nature is meant to do the work--so let her.
Leave a nice layer of leaves on flower beds and at the base of shrubs as a natural mulch.
Most annuals can stay. They'll disintegrate beneath the winter blanket of snow. Impatiens, for example will shrivel up and disappear after a few weeks of cold. What's left can be swept out by hand in early spring. The decaying root system will naturally integrate the soil with valuable nutrients, so leave them in place. Pick a spot in the yard, and start a compost of potted plants and large scale clippings. Consider the neighbor's line of sight when chosing a location. The back of the garage may be out of sight for you, but a direct hit from the Addams family room.
Clip the top third from sturdy stemmed perennials like phlox and shasta daisies. The remaining stems will collect snow and assist in the insulation of roots from the freeze and thaw of winter. For winter interest keep big headed plants like sedum and hydrangea intact. Do not ever cut back early spring blooming or wooded plants and shrubs like rhododendron, hydrangea, butterfly bush or lilac in the fall. These should be trimmed, if needed, right after bloom in the spring.
Take the basket from the mower and mulch leaves into the lawn.
Reduce the pile at the curb and increase the energy in your garden. Nice balance.