There isn’t much more that can be done without completely replacing the meshes, and if you like the overall look of the original hairstyles this may be the best compromise between keeping them in their messy state and completely replacing them. This mod by AnOldFriend mitigates the issue without even raising the resolution, but by making detail sharper and more defined, reducing the unpleasant greasy effect by a lot. Hair textures are so low in resolution that every hairstyle looks like a completely unappealing and greasy mess. One of the main graphical problems in Skyrim is hair.
If you like your character to be a little more “Highlander” (or just to bathe less) you can also find Geonox’s Dirt Maps and Facepaints here.
If it is for you, you can download it here. Like every beautification mod, this isn’t for everyone (even if I’m hard pressed to understand how one could like the drab original textures more, but to each his own).
