My season is short. I find it best to treat the "primary digester" compost bins as separate systems. I add, fill, add, fill, mixing a few times a week; and when it's running hot and pretty full, I leave it work. Then I start filling the second one. It doesn't have to be perfect like commercial compost; it will finish working in the soil.

Some people use a screen, somewhere between 1/2" and 1" mesh, to filter out the unfinished stuff and send it back through the system.

I also have a slow pile, a multi-year project for gnarly stuff like sunflower stalks and tough, fibrous beasties. I just keep adding on top, stomp and chop with a sharp shovel, and down the road there's a lovely pile of finished material at the bottom. (I also deposit "liquid vitamin x" as I'm walking by, for the nitrogen and phosphorous; but that's another conversation.)