Cornell and most web sites say used coffee grounds are a C:N ratio of 20:1, if that is what the '%' in your OP was asking. If not, sorry, many people prefer to avoid any discussion of C:N, or greens vs. browns. I'm afraid the whole leaves will not do much to generate heat with the grounds, leaves must be shredded to break down quicker. I shred my leaves four times with my mower (when my chipper/shredder is broken). When the Starbucks grounds were quite wet, I used to break open the bags and let them dry in the rubbermaid containers in the garage or basement. If you kept them too many weeks, a white fungus-like growth began. I remember a woman a few years back who wrote on this forum that she found a mix of grounds and paper worked well -- or at least 'smelled good'.

I think corn husks are a bit like leaves. If they are tender and green when harvested as corn on the cob for dinner, perhaps they are 'greens'. The corn I scavenge from my meighborhood's fall decorations is grown to hard dry maturity, and the plant tissues become 'woody', right down to the husks. Like a tree moves nutrients out of fall leaves to conserve energy, corn must do this as well. putting everything it's got into those precious kernals. The husks I have are definately browns. They're tough and papery. Likewise, take straw for another example. A young wheat plant would be a 'green', but left to maturity all the nutrients go to the seedhead and the plants turn brown in the ground before harvest. What's left is dead straw-a brown. disclaimer--this is what I personally think, from my own occasionally tenuous logic and experience. I'm pretty smart, but I was wrong once in 1988, so bear that in mind.

When we don't have snow on the ground, I've been more or less continuously creating lasagne beds since Fall '06. It is my preferred way for creating new beds and I have plans for a couple new beds, large woodland gardens, a large shrub border, etc. so it is an ongoing process. I start with 3 basic layers - Cardboard, coffee grounds, leaves (brown-green-brown). I lay down sheets of cardboard, 1 or 2 layers thick. Then spread 1-2 inches of used coffee grounds (with filters). Then I spread 2-3 inches of leaves. Then perhaps grass clippings, garden debris, compost, partially finished compost, manure etc. Anything goes on top of the 3 basic layers. I prefer to wait awhile before planting, because I am trying to smother a thick layer of weeds underneath. Apparently you can plant right away if you dig some soil into the planting hole. If I want an "instant bed" or an instant planting hole I use the "break your back" method - because I have to dig out weeds, rocks and roots. No simple turning over, pile a little on top, and that's it! Lasagne smothers the weeds (or grass) underneath. It adds organic matter to the soil. It raise the soil level some, depending on how deep your layers are, but for the most part the layers break down and settle a lot more than you would think.

A few years ago when our Starbucks was refilling the bags we accumulated a lot of them, so we made a scarecrow. The bags were great as stuffing for legs & arms plus cut in strips for hair. The hair was stapled on to a flat piece of scrap wood for the face. We did long layers & short bangs to flutter in the wind. We screwed on lids from various plastic containers for the eyes, nose & mouth plus cut some red lid for a better smile. The 6 year old daughter of my niece promptly called it Jessica, the name of our married daughter. We have no idea how she got that idea, but the name stuck. It was fun to have a named scarecrow and the 6 year old went to it right away when she visited us to say hello. It was the funniest thing.