I was inspired to create this mod after looking for some hair additions to the bretons (because they have the lowest hairstyle variety on the game) and finding out this mod here on Nexus

Vanilla Hairstyles Expanded - Breton
wich is a pretty good mod but with 3 major "flaws", the first one was that it brings the bald versions of the other races that we don't need, the second was that it forgets about the 2 nord hairs (male and female) added by Bloodmoon, and the third was that this mod only works for the Breton race, so i decided to make my own improved version of his idea, thats why my screenshots and the way that my mod was made is pretty much based on his, i used different IDs to make my mod compatible with his, but i don't recommend to use the 2 mods together because you will get duplicated haircuts for the Bretons.

Important Note: even though i have taken some inspiration, all files are made by me from scratch using the Construction Set, Mesh and Texture editing(already added the assets credits for the authors), i have not edited any files without permission or stolen. The mod created by Cyroladd had no intentions of making it works with Imperials, Nords, Redguards or Mer and has a different approach to the game. What i considered "flaws" are actually features from his mod that only focuses on the Breton race.

The biggest difference between my mod and his is that i made it works for all human races. (Now Mer races too)
Also its good to mention that all hairstyles of these 4 races are playable between them, i only put some of them on the screenshots to give a general idea of how it works.
All females from each race now have in total 23 hairstyles to choose
All males from each race now have in total 27 hairstyles to choose
Mer Update:
All females from each race now have in total 38 hairstyles to choose
All males from each race now have in total 41 hairstyles to choose

I also added as optional the textures that i made and used on the screenshots that makes the Dark-Brown hair into Black hair.

For some strange reason the Redguards Males have 2 bald hair models (b_n_redguard_m_hair_00.nif and b_n_redguard_m_hair_05.nif), this has nothing to do with my mod since my mod don't change any vanilla asset, if you don't want to have two of the same model that only change the ear texture, feel free to use any model replacer you like and change one of the 2 .nif files

Recommend to be used with:
Barbershop - Face and Hair Recustomizer for Player and NPCs
if you use Script Extender you can change the hair and reset to original anytime you want.
Familiar Faces by Caleb 
Because it looks really good, actually it looks way better than the vanilla ones on the screenshots.
EDIT: it's even more recommended now with the Redguards update, since this update uses the assets from this mod, also take a look to the Upscaled Textures, kart_FUT_2 for vanilla
More Heads and Diversity Expansion + Upscale Textures
More faces to customize with the upscale version for better quality (kart_FUT_MHD), More Heads also adds a little more hairstyles to choose for other races, the only problem is that it uses the vanilla meshes, maybe i'll make a patch that uses the models from Familiar Faces, because it's a mod that i really would like to see with some vanilla improvement and mixing the two mods would look so cool(good to mention that these two mods are free to edit and improve, of course i'll leave the credits).

Edit: (WIP) I'm trying to update the meshes with Caleb models, in order to use with my mod, also including some of my own edits.

Edit 2: Finished, i recomend to use My Edited Version instead !!

Dim's Khajiit Head and Hair Pack + Pluginless Khajiit Head Pack
For the Khajiit i recommend this one, a lot of cool hairs and faces to use, also if you already uses the Familiar faces version, consider replacing with the Pluginless Khajiit, it will replaces with a more improved vanilla friendly models, and Dim's Khajiit was made to match this one.

Tamriel_Data and OAAB_Data
Just like this 2 mods complements each other, my mod fits so well with them, even though they are an asset repository, they actually adds more heads and hairstyles based on the original concept arts of the game, the bosmer are specially the best fitting since they don't have too many hairstyles, now with this mod they have!

MWSE Random NPC
This mod creates random NPCs with randomized hairstyles, making it 100% compatible, now you will see some random NPCs with the hairstyles added by my mod, also check out MWSE Name Randomizer for MWSE NPC Randomizer for some lore friendly generated names.

Repopulated Morrowind + Yet Another Guard Diversity + Watchmen on Vvardenfell + Riders + Sload and Slavers + Racer Dust Arms and Armor + Racers and Sload and Slavers Weapon Sheathing Patch + Wares Ultimate
These mods don't use random hairstyles like Random NPC, but it is great to be using it all together, the cities will look more complete, less empty, more varied and with an almost unnoticeable FPS loss.

This mod should be compatible with any other hair and face replacer as long as the races has the same proportions, otherwise you will probably see some clipping (with the exception of the added nifs since they wiil need new mesh edits, it shouldn't be that hard since i already did all of the hard work, just maintain the files names and everthing should work).

Should have no problems working with OpenMW or MWGE XE

Update 1.4: All Mer now share their exclusive hair with Themselves too, from this point any future update will probably be a bugfix or some other optional patch.

Update 1.3: in order to do the next update i learned how to edit mesh using blender, wich means that now i could fix the problems with some models, wich means that there's no more need to be using custom textures to work, now you can use any texture replacer and the mod will use them, also fixed some problems with the IDs being somehow confusing and changed the name of the esp in order to prepare for the Mer update.

Installation: Just drag dan drop "Datafiles" into the game folder, if you have the old version of this mod and wants to update just overwrite the files when asked.

Credits for the assets that i used for update 1.4:

• Caleb AKA Explorer1911 for the improved quality of the vanilla models.