All my outdoor rabbits are in sheds. I love going to clean them out. I have a little plastic child's stool in each shed that I sit on and then I arrange all the bags (straw, newspaper and rubbish bags, hay and yummies) and get started.
The hares have four litter trays (two main ones that they use a lot and two hang out ones that are usually dry).
The quad have three trays.
The indoor pair have two trays.
Mind you, even with sheds it is waaay nicer going out in dry, preferably sunny weather.
Those big checked bags which zip up make great hay and straw carriers.