There are a few rule of thumb ideas that you might want to give a try in your coop. *No rules are hard & fast*
Rule # 1 Roosts should be higher than your nest boxes. Because the hens will produce more fertilizer during their sleep than at any other time
, it would be a good idea to have some sort of removable dropping board under the roost. This way you can clean just that board every morning, removing a lot of the coop's mess. Easy Peasy.
Rule # 2 Nestboxes are generally at least 12" above the floor. Most hens appreciate a small perch in front of the opening, so that she can check things out before entering the nest. If possible, put the nests into a darker corner of the coop.
Rule #3 Hang the waterer/feeder at shoulder height (chickens' shoulders, not your's) so that they can't kick dirt into them. Another option is to mount them up on a sturdy box.
Look at the coop and 'see' how you'll empty the droppings board, and gather eggs and do the other chores. You want to make this easy on yourself.
If you're saving space, then perhaps you can put the feeders under the dropping board. Just make sure that nothing can drop into them from above.
And do remember, the hens don't care as much as you do pertaining to the layout.