I have been tinkering with this mod for years, but it shouldn't take too long for you to make a version for yourself.

You should start by downloading these for a baseline:
7.6GBKartoffels' - Cleaned Skyrim SE Textures [POST_1.6]
10.9GBIconicDeath's - Project Clarity AIO  [Half Res Loose]

Then pick and choose which texture mods you would like to have, links to many of which are on my main page. NOTE - you can download any mod you want and tinker with it for your own personal use.

For texture files locked away in a BSA, use 
AlexxEG's - BSA Browser (with .BA2 support)

===========================================================
Create a folder /MyAwesomeTextureFiles01/
create a sub-folder /TempTexturesA/
and one more folder /textures/

Put all your textures in- 
/MyAwesomeTextureFiles01/TempTexturesA/textures/

Remember when compiling, the latest file version wins. 
Start with CSSET files, then overwrite with Project Clarity AIO.
Add vanilla upscales, and then your own personal tweaks.

Now, if this folder is bigger than ~18 gigs, 
not everything is going to fit. Min/Max wisely.

Got a build you think you'll like? Great, time to test.
Create a zip file from the loose textures; I use 7-Zip from PortableApps

Create TempTexturesA.7z - this should have the /textures/ folder.

Drop this file into your Mod Organizer, I use Vortex. 
Mod testing is exponentially harder without a mod organizer. Do not attempt.

Enable TempTexturesA.7z and then load up Skyrim. 
Everything look good? No? Go back and make TempTexturesB, etc.

Got TempTexturesX.7z that you like? 
Congrats! You can stop here. 
Early versions of this mod were just this. 

===========================================================
You want to make BSA files? Okay, you asked for it.
Utilizing Gka1's Cathedral Assets Optimizer, go to 
/MyAwesomeTextureFiles01/ and select /TempTexturesX/

*check* Show advanced settings
*check* Create BSA
UNCHECK Delete source files
*check* Create dummy pliggins
*check* Allow compression
*check* Separate textures BSA
Maximum size = 2.2

Click *Run*. 
This will take awhile. This will create files that look like:
TempTexturesX0.esp
TempTexturesX0- Textures.bsa
TempTexturesX1.esp
TempTexturesX1- Textures.bsa

If any of the TempTexturesX#- Textures.bsa files are larger than 2.01 gigs, 
it will cause Skyrim to *CRASH*. 

===========================================================
If you wanna turn these esp files into ESM, read on, otherwise skip section.

In your /MyAwesomeTextureFiles01/ folder, 
select ALL the TempTexturesX#.esp files. They're quite tiny.
Open your /Skyrim/Data/ folder and move, yes *MOVE* them there.

Using utumno's Wrye Bash
, select EVERY TempTexturesX#.esp,
right click, and select "Add ESM Flag". Do this for each TempTexturesX#.esp

Open your /Skyrim/Data/ folder, select ALL the modified TempTexturesX#.esp

and move, yes *MOVE* them back to /MyAwesomeTextureFiles01/

===========================================================
Alright, so we've got our TempTexturesX0.esp & Textures.bsa files.
We're gonna MOVE them FROM /MyAwesomeTextureFiles01/
TO a NEW folder called /MyAwesomeTextureFiles02/
leaving behind the /TempTexturesX/ and it's /textures/ folder. "Backups".

Create MyAwesomeTextureFiles02.7z - this should have the TempTexturesX files.
Drop this file into your Mod Organizer, I use Vortex. 

Enable MyAwesomeTextureFiles02.7z and then load up Skyrim. 
Everything look good? No? Go back and make MyAwesomeTextureFiles03, etc.

Got MyAwesomeTextureFiles09.7z that you like? 
Congrats! You can stop here. 
Middle versions of this mod were just this. 

===========================================================
Oh, you actually want to create Skyrim - Textures.bsa replacers? Yikes.

Alright, if you were quite lucky, you have exactly 9 texture.bsa files.
DELETE the TempTexturesZ#.ESP files, 
and RENAME the TempTexturesZ#- Textures.bsa files to EXACTLY these:

Skyrim - Textures0.bsa
Skyrim - Textures1.bsa
Skyrim - Textures2.bsa
Skyrim - Textures3.bsa
Skyrim - Textures4.bsa
Skyrim - Textures5.bsa
Skyrim - Textures6.bsa
Skyrim - Textures7.bsa
Skyrim - Textures8.bsa

If you have MORE or LESS than this, then you have to fiddle with the ini files, and are beyond my help.

But, if everything went right, 
put Skyrim - Textures0-9.bsa into a foldler, /MyAwesomeTextureFiles92/
Create MyAwesomeTextureFiles92.7z and test in Vortex.

Got MyAwesomeTextureFiles99.7z that you like? 
Congrats! You can stop here. 

If all your source mods were open permissions, you can upload yours to Nexus.
Otherwise, you can just use your new texture mod, and... play Skyrim?

===========================================================