This mod edits most of the headwear in Skyrim to allow circlets to be worn with them.

Requires:
Skyrim
Dawnguard
Hearthfire
Dragonborn

Install:
Just use Nexus Mod Manager or copy CircletEnabledHeadwear.esp and enable it.

Known Issues:
Some helmets clip with circlets, I cannot help this without making new meshes for all those helmets which could make them look odd w/o a circlet on.

Can also be used with Wet and Cold - Ashes so face covers can be used with many helmets.

Update:
V.6: Now includes Immersive Armours! (ONLY VERSION 6, DO NOT USE THIS WITH VERSION 7!)
V.7: Missed a Novice Hood.