I put scratch under their roosts in the morning so they "make their beds," meaning they scratch around fluffing their bedding and mixing in the poo so there are no clumps and is no odor. I also sometimes toss some scratch out in the run before I gather eggs to lure all the fakers out of the nesting boxes.
About food waste: when I was using store-bought feeders and feeding crumbles we were going through a crazy quantity of feed. One day I paid very close attention to what was going on and my flock wasted 90 lbs of feed before noon. You read that right ... 90 lbs, 3 feeders full, nearly 2 bags of feed. They just beaked it out of the feeders and then ignored it. I tried to get them to clean up the mess by not giving them more food, but feed on the floor gets nasty pretty fast.
We switched to feeders we made from large drain pipes -- a longer length of drain pipe as the "hopper" attached to a shorter piece by an angle connector, the shorter piece has large holes drilled on top (all edges are sanded smooth). The curved sides of the pipe and the holes mean they can't beak the food out. But crumbles didn't work very well in these feeders. We switched to pellets and this system is working great, whole grains would also work well in feeders like these. We go through a lot less feed, and if any pellets get spilled the flock cleans them up before they start to get nasty.
After switching to the home-made feeders I had to remove and replace the deep bedding in the coop because it was so rancid and nasty from all the feed that got mixed in. I kick myself for not figuring out what was going on sooner, but I was new to chickens and having to figure out SO many things. And I have so many chickens.
Repeating myself: I'm not at all happy with commercial chicken feeders or waterers.