I've got just a few.
My fort has a large central pillar of up/down staircases, often 3x3, sometimes larger. There might be alternate routes, but they are on the end of long corridors and often marked as restricted: I don't intend them to be used for anything other than emergencies, and they rarely do more than link to levels of crypt or bedroom levels, or something like that. My corridors are two tiles wide, so that it's easy to pass each other, but it's still easy to close the corridor off with two doors.
I must -simply must- give every adult dwarf their own bedroom but I don't bother giving beds to the dwarf children and babies: They go in the transient bedroom, which is a room somewhere central where I've got furniture stockpiles and several set up beds and dormitories. It seems you don't have to make a bed into a dorm to have them sleep in it. The adult dwarf bedrooms are at least 3x3 each, with a bed in the centre, and a cabinet and coffer/chest. The walls are always double thick, and if I can manage it at all, a rock door. The door, coffers and cabinets are always made of a contrasting stone: My current bedrooms are in microcline, and almost all the furniture is diorite or slate, except for a few rooms in slate, which have microcline furniture and doors.
Crypts/mausoleums are dug usually in an ore-bearing area, so that I can just bury the dwarfs in the dug-out ore veins. I have a pile set aside for coffins, slabs and doors, and a masons and craftsdwarfs workshop next to that especially for the "gravediggers". If a dwarf is awarded a tomb (for service, such as mayoring, or because they demanded it, or because I really like their name or something they did) they never loose that tomb: It is theirs and only theirs forever after. I might put statues, stone coffers, and other things in their tomb as well.
My champion, if I have one, always walks with a crutch. If there aren't any dorfs with crutches, I just don't keep a Champion. I never bring, buy or make wooden crutches any more: All the crutches in the fort are made of metal, the heavier the better. I have once successfully had a crutch bearing Champion beat a giant to death with her crutch. It was epic, thankyou to whoever taught me that trick...
I try to never engrave floors, it's ugly. I dislike turning engravings off: I want to be able to see the engravings in some places, like the time someone decided to engrave the election of the mayor all over the dining hall walls, and there were twenty dwarf faces smiling up at me (The dwarf is surrounded by the dwarves...) I like engraved walls, because it's pretty. So I don't engrave the floors, just smooth them, or, if it's a dirt floor, I might manufacture stone or wood floors. And yes, I don't use any custom tilesets, I've got a vanilla copy of DF with no additions like therapist or anything... God I wish I could engrave built walls...