When I first started playing DF, I did a lot of theorycrafting and thinkering trying to design the most efficient, space-filling, and pretty bedroom and fortress designs.
Then eventually I realised that dwarves being dwarves, all that careful thought goes out the window the first time ten of them all decide to go try to collect the fingers of the poor berk who just got assaulted by the berserk, artifact failed moody dwarf.
Or by the unfortunate intersection of fortress and useful mineral vein.
Or by the nasty habit of water, magma, and other fluids (eew) where they get in your way no matter what.
Now I just try not to make it too asymmetrical, and I just use boring three-wide hallways with 1 x 4 rooms coming off of them. 4 squares = bed, chest, cabinet, door.
My nobles used to get three rooms, a 3x5, a 4x5, and a 5x5, for their bedroom, dining room, and office respectively.
Now I just make one 5x5 room that is attached to my main dining hall, and I make the room big enough that it includes the dining hall. That way when I get an artifact mechanism, or chair, or whatnot, I can put it in there to both satisfy the count's request for a stupidly expensive room, and to give the peons 'dined in a legendary dining room' and 'looked at an awesome piece of furniture lately' happy thoughts.
The best part is that I can do this for five or so different notables with one dining hall, and by manipulating the tiles I start defining their rooms from and exactly how many steps of embiggening I do to each room, I can make sure that no one has a room whose value is above their station.
Yeah, I'm lazy.