1. Skyrim Cosmetic Armor Slot Mod 1.12.2
2. Skyrim Cosmetic Armor Slot Mods
3. Skyrim Cosmetic Armor Slot Mod Minecraft 1.12.2
4. Skyrim Cosmetic Armor Slot Mod 1.7.10

As probably you know, Vilja, from http://skyrim.nexusmods.com/mods/26393 didn't equip unarmored clothing while wearing armor. This is to avoid weird outfitting when armors and clothing didn't use the same slots, as she using a multislot armor and a dress at the same time, or a full daedric armor with clipping sixy lingerie.
There are though, some complements that would be desirable to be an exception to that rule, but then again, it would be interesting to know when a clothing from another mod uses the same slot.

At Nexus-mods.com, we are giving you mods download files for free. Mods are fan-made More Armor Slots that will remove your disappointment of some More Armor Slots as they miss some points that make them perfect. The update not only flags the mod as a master, but also adds a ton of new features, including: A new island to the north, with 5 new locations (and 4 locations in Lastendell) As part of the island, a new quest, giving a new custom-made armor set. Also a new custom weapon can be found at one of the locations.

Skyrim Cosmetic Armor Slot Mod 1.12.2

Finally, the slots used by different armors could be useful for other modders. So, I would ask you to comment which non-vanilla body slots use different mods not included in this list, despite them being clothing, armor, or whatever. I know there is already a consensus, but also know that there may be exceptions. This is not about what should be used, but what is being used currently:
Here is the list I have so far:

Skyrim Cosmetic Armor Slot Mods

44: scarves [scarves of Skyrim]
45: scarves [winter is coming] and wraps
46: cloaks [winter is coming, cloaks of skyrim]

Skyrim Cosmetic Armor Slot Mod Minecraft 1.12.2

47: backpacks
48: bandoliers (back left)
52: bandoliers (left side)
53: bandoliers (chest)
55: bandoliers (back right), lanterns (back), angelic halos and demonic horns
56: blindfold (right eye and both eyes), goggles, cloaks [cloak of the lace for lady]
57: bandoliers (front right), lanterns (front), blindfolds (left eye)
58: bandoliers (front left)
59: bandoliers (right side)
60: left hand rings

Skyrim Cosmetic Armor Slot Mod 1.7.10

I added the name of the mod between '[' ']' signs, when different mods use different slots for the same item type and ‘(‘ ‘)’ signs to point where in the body the item model goes, when a mod adds an item type in various body slots. Besides slots not included, it would be helpful to know if any of the added ones is outdated or simply wrong.