Here's one of my old bedroom layouts from a fort I had a while back.
Very pretty
I use a basic modular (boring) design at the moment, I am still fairly new and have yet to try the engineering options apart from the very basics (drawbridges and floodgates). I will get around to it eventually.
First level in is my storage area with a little area to the north west where I drained a small pond and made an underground farm for shrooms.
Workshop level with magma forges and smelters in the south east corner. two corridors to the east and west leading to mining shafts.
Communal level with the magma channels to the south that fuel the forges upstairs. The hospital is to the north west along with the wells, the kitchen area to the right and the rather modest dining area to the north. The rooms to the east are prison cells though I havent had to use any yet as everyone is happy.
Bedrooms for the grunts. (x2)
Noble area. the Dukes quarters, office and dining area to the south west with areas for the Mayor, sheriff and (spare) just north. the entire east side is reserved for the king/queen with a large throne room on the south east and bedroom/ dining area in the north west section.
And finally the crypt. Pets and grunts are buried in the north west section with nobles buried in the tombs in the southwest. The large room in the south east might be used as an arena and the rooms in the north east are just spares.
Apologies for the uncropped images, paint refused to let me crop them and it's late here and I can't be bothered to fight with it.