When my coop is functional, I like to use a three stage process. Clean shavings and bedding go into the coop. When it starts to look dirty and discolored, I push it all out into the run. Out there the bugs can get to it, and the chickens keep mixing it up and pooping in it. Fall leaves and garden clippings go into the run, too. Eventually I rake/shovel out the run into a pile, and let that sit, mixing it up from time to time. Eventually I declare it compost and add it to the garden.