I like a strict floorplan layout (although vertically I'm at the whim of cavern intrusions... but I increase inter-cavern layers to give me a good chance of a nice solid block). That's corridors, stairs and general room areas, not necessarily the actual room configuration or indeed what they're used for.
I also like to use exactly the same building materials for all aboveground structures. If I have to vary, I'll vary according to a rule developed in light of ground conditions, like "all ground floor walls and stairs are sandstone", but "all first floor[1] walls and stairs/etc being diorite". Although I do prefer an all-white structure. (Some minority stone, usually something yellow, or perhaps green olivine or blue microcline or one of the red coloured ones, is used as 'scaffolding' bits, to make it obvious that I'm removing it later.) 'Infill' walls, below ground (where I've dug gems out of future magmaduct walls, or have (despite my best efforts) intruded into a cavern void) are usually built of the general strata material that exists elsewhere around the area.
And all non-temporary constructions must be blocks (from before recent changes). If I can make workshops built of blocks, even better, including rebuilding mason's workshops out of a block, once the original has made blocks to build out of. If I'm setting up specialist block-masons to create any given block-material, I'll want the workshop to be of that block-type.
I also care about the material (and even quality) of mechanisms matching, within 'from' and 'to' pairings, in linkages. And would like to match them to lever, which I would like to match (where applicable) to bridge or drawbridge material (of blocks, again, where built of stone).
I don't avoid danger-rooms, but rarely get them ready because if the ones I start to set up were ever complete they they'd be at least 3x3 (minus room defining furniture spot) and probably bigger and composed of exactly the same quality and material of training spear and linking mechanism-pairs, back to whatever trigger I have set up. Getting multiple no-quality featherwood training spears (even with trading) is a lot harder than it seems.
I am far less fussy about things like trap-overkill corridors, etc, but I stick to cage-traps only. More a hindrance than a help, so I suppose that's also a house rule along the lines of the thread question.
Also, I'm very protective of my dwarves. Probably why I largely used ranged troops from atop sealed-off-from-the-outside walls, when enemies arrive. A lot of effort is put into giving myself multiple sealable/controllable entrances, and even time-wasting entrances with switchable through-routes and back-ambushing by-ways attached, accordingly, depending on whether it's friend or foe that's heading into my fortress-heart.
And never let any dwarf idle, for any longer than can be helped. Keep the buggers busy. (There's always hauling to be done. And if there isn't, I'll make sure there is...)
[1] The (sensible) UK definition of "1st floor", with the ground being "0th".