I had a look through my old daedric shrines and noticed some slightly jarring issues with some of them, especially Ald Uman.
The biggest issues are that there are 2 statues in this interior, which is never done in vanilla except for unique shrines. 
Secondly, the cell names were not adhering to vanilla either. Third, there were some general cluttering (excess bone clutter) and design deficits (missing scamp) that I aimed to fix.
Here is a rough overview of things that I changed in this ESP file:

1. Renamed cells 'sepulcher' to 'inner shrine' and 'outer halls' to 'shrine' 
2. Added clutter to undercluttered areas, removed clutter from overcluttered areas
3. Moved the contents of cell 'antechamber' into cell 'inner shrine'
4. Made the inner shrine smaller, removed half of the bone clutter, made the statue smaller
5. Removed the 2nd statue in the outer halls / shrine area, as 1 statue per ruin is customary
6. Changed the ambient color to be a bit more green, especially in the inner shrine
7. Replaced the skeleton in the cave with an ogrim
8. Added another daedric throwing dagger in the locked room
9. Generally added more loot as it was quite sparse for the amount of foes
10. Improved the pathgrids
11. Slightly increased the level of, and moved the NPC near the entrance into the nearby locked room (as was my initial intention)
12. Placed a unique scamp called 'Cramp' into the locked chamber that has a greeting and then flees from the player (as was my initial intention, idea acknowledged by Cicero)

That's about it. it may sound like a lot, but the initial layout and feel is practically the same.