@Blizzlord, then why did you comment?
"No plan, no aesthetics, no design" is a perfectly valid strategy for fort design. It maximizes the organic nature of the fortress. Other strategies balance other aspects.
Lately I've been building around a 3x3 staircase. I've got a peasant apartment strategy that I love, which is basically modular 11x11 blocks sliced in half vertically and then into 1-urist slices horizontally, with three staircases in the center. Let's see if this works:
╔═════╦═════╗
║ΩӨΠÆ+║+ÆΠӨ+║
╠═════X═════╣
║ΩӨΠÆ+║+ÆΠӨ+║
╠═════╬═════╣
║ΩӨΠÆ+║+ÆΠӨ+║
╠═════X═════╣
║+ӨΠÆ+║+ÆΠӨ+║
╠═════╬═════╣
║+ӨΠÆ+║+ÆΠӨ+║
╠═════X═════╣
║+ӨΠÆ+║+ÆΠӨ+║
╚═════╩═════╝It's incredibly quick to designate, and with the beds where they are, rooms are created exactly the right size without the need for doors. Note the extra space for statues if somebody gets too emo. I generally have two levels of eight of these blocks arranged in a square, with an access level in between. That leaves plenty of space for noble quarters, jails, and such.
A couple levels up is the magma shop, which means that there's magma conveniently above the noble quarters. Below is a great big dining hall, which I want to be multilevel with both magma and water flowing through. I've accomplished this once, with the
drawbackbonus that the magma kept overflowing onto the nobles' dais. I'm still working on ideal layouts for these things.