I deliberately didn't do a last mowing until after the majority of the leaves had fallen -- oak, hickory, & maple. And Southern pine needles are coming off right on schedule, too. So I mowed 3 acers of mine and an acer of the neighbors -- they were thrilled to let me do their last mowing in exchange for "leavings," pun intended. Round and round and round and round we go, mulching with my first-ever riding mower, letting the machine do the work. For instance, a 2'x60' pile of first gathered leavings was further mulched down to 2'x12'. Lots of air in those leaves before processing. Lots of those piles to play with.
(The grass is not sewed, never fertilized, just what happens around here when you mow a hayfield with a lawn mower for 70 years, you get thick hardy fescue that grows insanely well in our climate.)
So what I ended up with is pieces of roughly and finely chopped leaves, pieces of grass clippings, and pieces of pine needles, in about equal ratios. Some loads had more pine needles, some more grass clippings, some more leaves, depending on the part of the yards where I was collecting. But on the whole, since I used 2 rakes as big hands to load my pull-behind mower trailer, and bare hands to scoop out of the trailer, I'm pretty sure the ratios are 1:1:1... ish.
Here's what I did with it -- and not done hauling yet, hehe.
1) Filled 4ea 4'x4'x4' compost bins scattered around the property with the loose mixture -- figuring it will settle and I can add household scraps and more yard waste over our relatively mild Southern winter. Wet it down with garden hoses. There are 1" gaps between each layer of true 1"x6" slats. Plenty of air. Half the bins have lids, half do not. Half the bins are in sun, half in shade... experimenting to see what works best here. These four bins will have dog poo added to them as well as they settle, but these are strictly for flower compost so I don't care about the poo.
2) Filled a rabbit wire "fence" that is about 3' tall and 12'x12' round that is over a bad hole in the yard -- hole problem solved. The wire is jagged, so I too a cleat and "rolled" the wire around both ends, then stapeled to hold it togehter, then I drilled holes so I can use fence wire to hold the two pieces of board together. Can't water this pile, too far from hoses, but open to elements and sun, we'll see what happens by Spring. I thought about tarping it to keep stuff from blowing away, (my precious!) and removing the tarp when we're scheduled for rain... Mmm, maybe a layer of staw, which I have several rotting bales. This is now the Big Round Bin. Neighbors are talking about it already.
3) Filled 2ea 16'x32"x11" raised garden beds. Started with damp cardboard, then an inch of damp newspaper, both left out in the weather to pre-rot for 2 months. Then filled the beds to the top with the loose leaf-grass-needle mixture, dampened with garden hose. 3" of purchased mushroom mulch, dampened again -- this sqished the leaf mixture down so the mushroom was level with the top of the boards again. Then 3-6" (heaped in the middle) of purchased topsoil/aged cow manure/mushroom compost all roughly mixed but not screened, dampened again. THEN covered the heaping beds with black plastic stapled to cleats which were screwed into the sides of the beds. The hope is the whole thing will cook under the black plastic but even if it doesn't, I should have "something" to plant in come spring...
More more more, what to do... Bags seem like a great way to keep stuff from blowing away -- but are spendy. I think I need another rabbit wire Big Round Bin but closer to water... mmmm... where to put it.
I know, I know, most people turn compost bins. Seems to me that's a lot of wasted energy when time will take care of everything -- just looking at the acers and acers of woods surrounding me, no one turns those leaves over and it's black gold under there. We'll see. I'm patient and have LOTS of materials to work with. I've been wrong plenty of times before, so we'll see.
The natural method you describe for letting the leaves become a mulch in place certainly does work but it really takes a longer time than a regular mulching system. If Time is not so important why not?