I've been wondering the same thing -- there was a thread on GW recently about leaving most perennials, etc. and cutting back in spring. The idea was that leaving perennials both provided seedheads for birds and provided a structure to catch leaves, etc., providing natural insulation that was better for the plants than cutting them to a few inches and cleaning out the beds. I just talked with our town arborist (also a landscape designer) this morning, because I wondered about the pros and cons. He suggests cutting back to 4 or 5 inches (so no seedheads) and then piling leaves on the beds to protect the plants.

I also wondered about leaving leaves on the beds that had exhibited (as my maples have) fungal growth this summer and fall. My instincts were to get rid of them, since I've always thought of the fall cleanup as designed in large part to reduce the potential for mold, fungus, etc., to "overwinter" (though obviously, Mother Nature has no such concerns, since she's arranged for all those leaves fall on the forest floor! ;)

So I'm planning to cut back only the perennials that I know will be mush by spring, and blow the leaves from the lawn onto the beds this year. I'd be interested in hearing what others are doing...

Things that are hardy and subject to fungal problems, like peonies and asters, definitely get cut back.

Things that are marginally hardy, like chrysanthemums, definitely don't get cut back. Things deliberately grown for seed heads and winter interest, like many ornamental grasses don't get cut back.

Everything in between depends on how much time you have.

I try to cut back all my hostas because they get soggy and mushy and slugs just love to winter over at their base. I've cut back the asparagus and hope to get the rhubabrb and raspberries under control this coming week.

The phlox, asters and anemones look awful, so I hope to prune them back soon. Peonies too.

Ornamental grasses, Caryopteris, lavender and clematis get springtime haircuts.

My raised vegetable beds are cleaned scrupulously,limed, leveled, composted and readied as much as possible for Spring planting. Most of the stuff doesn't even go on the compost pile as overwintering organisms sometimes thrive in this environment. All kinds of bad critters can winter over to haunt the vegetable gardener the next season.
Ornamentals are a whole different problem. To clean or not depends on plants and available time.

Get rid of all the maple leaves. They pack down on anything they are left on and not good for any kind of winter protection. Considering the fungus problem now, don't leave them anywhere.

I use the oak leaves to protect my hydrangeas, and some of the beds that have perennials in them.

The veggie gardens get cleaned up and everything pulled out. The dead annuals get pulled.
Rake the oak and maple off the lawns, and any debris from the daylilies and hostas.

Containers are rinsed out if I have time and weather permits, otherwise they are done in the spring, just before planting in them.

I also always leave a marker that is labeled beside every perennial, so that in the spring, I know those sprouts are my plants and not some nasty weed poking through. I pull out all my morning glory vines and collect all the seeds for trades and myself, do not want reseeders if possible.

Birdbaths and any decor also come in about now, if not a little earlier. Don't want to have the cold and snow damage them.

I never do anything to my hydrangeas, rhodies or other perennials in terms of pruning until spring and I know what stems on the hydrangeas are dead and prune the rhodies after they bloom.

Fran

I have such large snail and slug populations that I choose to clean the garden in the fall hoping to not offer them a warm comfy place to spend the winter. The link below is to a recent post from Arbo_retum on this subject that you might find helpful. Kt

Here is a link that might be useful: spring vs fall