Pine shavings for me, in a 17 X 20 foot coop with a dirt floor (under several inches of shavings). Once year clean out in the Spring some time, with some not very frequent poop scooping where it accumulates on a stupid horizontal board built as part of the back wall of this former garage. (That, like Ridgerunner's poop board scrapings, goes directly into my composter.) Otherwise, I just keep adding shavings every couple of months, I buy a bale or two, open 'em and remove the plastic then let the chickens stir the piles o' shavings out flat. I usually open a bale under each large ladder roost where the most night droppings accumulate. Chickens spread it for me.