I spent a lot of time on texture mods created by incredible and talented modders - thanks guys, you save the (VANILLA) world! All the rights goes to you of course! I mixed them up, "shakering" those zip files and trying to find my personal best looking and immersive version of SSE. 
For that reason I have decided to provide to the community a list of what I think are the best texture mods issued and a little guide that will support you to create the perfect texture mix.

Follow this list, download S.E.T.O.G texture istructions and use NMM (always overwriting if needed, 2k or 4k is up to your rigs).  I play with a gtx 780ti with some 4k textures and FPS drops are minimal (some of the mods I think also free VRAM and improve FPS)

This inventory includes only mods that have been ported to SSE and that improve TEXTURES (and some meshes).
REMEMBER TO READ AND FOLLOW THE DETAILED INSTRUCTION PROVIDED BY EACH MOD AUTHOR in their mod pages.
FOR FRESH INSTALL: Unofficial Skyrim Special Edition Patch by Unofficial Patch Project Team IS ALWAYS THE FIRST MUST HAVE MOD.


STEP A.  - BUILD THE FOUNDATIONS WITH SOME LITTLE STUFF (THOSE LITTLE AND LARGE MESSY OBJECTS!)
-Static Mesh Improvement Mod - SMIM by Brumbek
-High Quality Food and Ingredients SE by Eraitico 
-Ruins Clutter Improved by raiserfx               
-RUSTIC CLUTTER COLLECTION - Special Edition by Gamwich      
-High Poly Project by LucidAPs 
-RUSTIC SOULGEMS - Special Edition by Gamwich and Saerileth    
-RUGNAROK - Special Edition by Gamwich                                          
-Book Covers Skyrim by DanielCoffey (I prefer the desaturated version)            
-Gemling Queen Jewelry SE by Saerileth
-RUSTIC COOKING - Special Edition by Gamwich           
-CC's Enhanced Ore Veins SSE Edition by ClearanceClarence 
-CC's HQ Septims by ClearanceClarence        
-Snazzy Furniture and Clutter Overhaul (SFCO) by Gutmaw 
-Forgotten Retex Project by JDAnchor (**I thank you twice my friend, for the mod and the SETOG banner**)
-HD Reworked Baskets - Special Edition by Halk_Hogan_PL 
-Skyrim SE Skill Interface Re-Texture by Arndas (many choices, but even default hd one are better than vanilla) 
-Training Dummies Retexture 4k and 2k by Haladoon
-Mammoth Cheese Retexture - 4k and 2k by Haladoon


STEP B.THE NOBLE SKYRIM TEXTURES -NobleSkyrimMod HD-2K by Shutt3r (WITH SOME BLOODLY MARY MODS "SHAKES")

-->NSM 


B.1 - Download and install following single packages (I know....but single packs are better to manage if you don't like some of them or you want to replace them with other mods). The All in one.zip will be also needed.
-01. NSM - SMALL TOWNS AND VILLAGES
-02. NSM - WHITERUN-ONLY
-03. NSM - SOLITUDE ONLY_4K
-04. NSM - WINDHELM ONLY (if you like the RUGNAROK - Special Edition by Gamwich CARPET in the main palace room, don't overwrite this mod)
-05. NSM - RIFTEN ONLY
-06. NSM - MARKARTH AND DWEMER RUINS ONLY
-07. NSM - WINTERHOLD COLLEGE ONLY 
-08. NSM - HIGHHROTHGAR ONLY
-09. NSM - FORTS ONLY
-11. NSM - STONE AND ICE CAVES ONLY
-12. NSM - MINES ONLY
-13. NSM - RATWAYS ONLY
-14. NSM - SHIPS ONLY
-15. NSM - BLACKSMITH SET ONLY
-16. NSM - CLUTTER ONLY
-17. NSM - NORMAL AND NOBLE FURNITURE ONLY
-18. NSM - 4K-ALCHEMY-WORKBENCH
-20. CAMPING SET 
-21. NSM - DLC DAWNGUARD ONLY


B.1.BIS Download the main file A. NSM - FULL PACK_v.5.3.0_2K - For Skyrim Special Edition BUT DO NOT INSTALL IT. 
We only need some files later on (see B.4). 
Same link of the above mentioned NSM packages. 
DO NOT INSTALL AND go ON with step B.2


B.2 - Download and install:
-HQ Towns and Villages by Anarin
-HD Road Signs - 2K and 4K by Valius  

Now we have to create our texture best mix (See some example in the IMAGES section):

B.3 - Manually download SSE Texture Pack - Osmodius by osmodius
Create a New folder on the desktop.
Open and extract all the content of the SSE pack .zip file in the New folder.

MANUAL DOWNLOAD  S.E.T.O.G. MAIN FILE in file section:
---> you have to use the S.E.T.O.G.txt to identify and select specific textures of the SSE Texture pack (already extracted) that you have to include in new separates ".zip" files (zip skill is needed to create new zip archives).

Create the .zip files mentioned in S.E.T.O.G.txt. (STEP B.3) including all the folders and textures indicated.
Remember that zip files have to include all the root starting from "data" folder to let NMM overwrites the mod installed before.

B.4. - Now we need some files from A. NSM - FULL PACK_v.5.3.0_2K - For Skyrim Special Edition (see B.1BIS)
Create new folder on the desktop (different from the one you used for SSE pack)
Open and extract the content of the zip in the new folder.

Follow the same procedure you followed in B.3 to create additional new .zip files with the support of S.E.T.O.G.txt  (STEP B.4).

As usual, remember that new created  zip files have to include all the root starting from "data" folder to let NMM overwrites the mod installed before.

B.5 MANUAL UPLOAD in the NMM all your custom .zip files created in B.3 and B.4 and install them overwriting as always

B.6 Complete with:
- JK's Whiterun by JKrojmal
- RUSTIC WINDOWS - Special Edition by Gamwich 


It was boring...did you survive? I hope so because it will worth it!
Now let's finish IT! (Mortal Kombat TM)

STEP C.ENVIRONMENT
-Skyrim Flora Overhaul SE by vurt 
-Verdant - A Skyrim Grass Plugin by Preeum 
OPTIONAL BUT NOT REQUIRED STEP: I have applied - thanks always to nexus community - a little fix for tundra grass to make tundra brighter.
I can't include any file since I don't have any rights on original textures, but,  if you are familiar with common programs to edit pictures, you can try a quick and dirty edits on the following verdant textures: 
Data\textures\landscape\grass\EGrass25.dds
Data\textures\landscape\grass\EGrass02tundra.dds 
Data\textures\landscape\grass\EGrass02fallforest.dds 
Data\textures\landscape\grass\33grassobjxx.dds

-Realistic Aspen Trees SE 4k by AceeQ 
-Realistic Water Two by isoku 
-Skyrim Textures Redone - Stars by Gorgulla 
-A Quality World Map by IcePenguin 
-Dust Effects by HHaleyy by HHaley - Darkjesusmn 
-Nordic Snow (aka HQ Snow Texture) by Erik1988 
NOTE: When Nordic Snow MOD asks, don't overwrite following two textures you add before in STEP B3 with "SSE Texture Pack LANDSCAPE 1-2 FIX.zip" since they are beautiful:
Data\textures\landscape\grasssnow01.dds
Data\textures\landscape\grasssnow01_n.dds

- Better Dynamic Snow by SparrowPrince
-Blended One Mountain SSE by Xannon98 
-Moar Daisies by WhiteLightning 
- Skyrim SE Improved Puddles by PCG4m3r 


STEP D.NPCs
-Better Males Remesh Favoredsoul-Chris57-Ratrace-Honkmansh-Vulchor 
-CBBE Calientes or  UNP Female Body Renewal 
-ApachiiSkyHair SSE by Apachii
-Bijin All in One-SSE by Mebantiza
-RS Children Overhaul by Azrael_wtf and Ranaline
-Beards by Hvergelmir 
-Improved Eyes Skyrim by missjennabee and Nazenn 
-Eye Normal Map Fix SSE by Mr Dave 
-Mature skin texture and body UNP UNPB 7BASE CBBE Vanilla(SE)by Maevan2 (take the file related to your body type/mod: VANILLA, UPN, CBBE..)
-RUSTIC CLOTHING - Special Edition by Gamwich 
-Immersive Armors by Hothtrooper44 (starting a new game you could occur in a "spinning carriage bug" - If so install Prisoner cart fix SMIM by kaliban71 or  Alternate Start - Live Another Life by Arthmoor and start with Helgen classic intro)
-Enhanced Blood Textures SE by dDefinder 
-4K Dragon Priest Masks of Immersion by LegacyArtist
-LeanWolf's Better-Shaped Weapons SE by LeanWolf and masterofshadows 


STEP E.ANIMAL AND CREATURES
-Bellyaches Animal and Creature Pack SSE by Wrig675 modified by Kelsenellenelvian
-SABRECAT by Kajuan 
-DRAUGR by Kajuan 
-DRAGON PRIEST by Kajuan 
-TROLL by Kajuan 
-Birds of Skyrim SSE Edition by Qasiermo and steve40 
-Bellyaches HD Dragon Replacer Pack (SE) by Wrig675
-GIANT by Kajuan 
-MAMMOTH by Kajuan 
-OH GOD BEES SE - More Bees-More Hives-HD Textures by lesi123 (Texture HD option)
-WISPMOTHER by Kajuan
-HAGRAVEN by Kajuan

STEP F.STATUES
-LeanWolf's Better-Shaped Talos Statue with GreatswordSE by LeanWolf   
-Stunning Statues of Skyrim by AnTiWoMaAgNoT(don't install TALOS meshes  but overwrite textures if you like them and dibella mesh from Highpoly mod)

FINAL STEP - USE LOOT
Then put Verdant after Skyflora Overhaul ; Realistic Water Two at the end of the load order.
Play!!

I hope you will enjoy the game with my S.E.T.O.G. - Special Edition Texture Overhaul Guide.
Note: Pictures and shots are made using also  True Storm and Realistic Lightning Overhaul