In my very earliest days (when my forum name described my fortress situations more, and for some time after while I dealt with other mortalities that suddenly became more likely) I used to dig to the very lowest layer of the map (pre-caverns, pre-SMR, only had to avoid actual magma pipes, bottomless caverns, pits, underground rivers, etc) and create a Tomb Complex. Big tombs for later noble-assignment (during life, to satisfy the Room Requirements, but may get 'inhabited' at some point) and lesser or equal ones unassigned until I had a body that could use one (pre-slab, but also pre-ghost).
I tried to make them a feature, at first. Technically they could be visited. Later I walled them up and/or (occasionally) arranged to fill them with liquid (red or blue type) as a hypothetical joke to play on any hypothetical tomb-raiders.
For a long time, though, apart from Room Requirement ones[1] I, a) hardly need them and, b) see no need to do anything more than a sarcophagus in a(n eventually) walled-off niche.
It would actually be nice to see that change. Well, not (a), but given any rare exceptions to (a) then subsequently (b)...
(Like pedestals/display cases, make them a feature. Perhaps token tombs ('unknown soldier'/generalised cenotaph, or set up a mythical hero's tomb just for the ambience/kudos/pilgrim-magnetism), where there's a lack of 'natural' raw filling.)
[1] These days a part of the "noble suite, 2x2 rooms: office/dining (main entrance, depending on if that noble uses an office); the other of dining/office and bedroom (adjacent internal exits) and tomb (final quarter, maybe led off bedroom because it'd be odd to connect to a dining-room).