Below is just Information to keep in mind and some tips as well.

To give players an idea with how this set up was made,
my current specs: (intended for 1080p gaming)
Nvidia Geforce 1050 TI OC 4GB VRAM
Intel Pentium G4560 3.50GHz
DDR4 2800 16gb ram
240GB SSD
1 TB HDD  (This is where I keep SSE W/ its mods but of course an SSD will decrease loading screen time)

50 - 100 GB is typically needed for a modlist like mine

Skyrim is optimized well for vanilla so I always get smooth 60 FPS. That'll change depending on just what size textures we install, as well as if we will use ENB (this list includes ENB alternatives).

Keep in mind:
Removing textures, ENBs, weathers, or even lighting overhauls SHOULD be safe mid-game.
But the general consensus is don't remove script heavy mods (or any mod that touches scripts really) unless you plan on starting a new game.

Along with that, it's a good idea to test each script/weather/lighting overhaul mod every time you install one. I've never really come across issues with installing textures all at once.

On another note, using 4k textures aren't really needed unless you can afford the VRAM. I personally have definitely noticed a difference in using them even with a 1080p monitor, but 
it is generally recommended you use 2k textures for both visual and performance benefit.

What if Skyrim SE updates??
Best fix I've found to prevent SSE from updating is going onto steam, right-click your games and choose preferences. Go towards the updates tab and choose the option; "update when I launch". This way SSE doesn't update unless you launch it from steam. Instead, you'll be launching SKSE64 through Mod Organizer 2.

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Main Foundation:

SKSE64 (it’s out of beta)
USSEP
SkyUI
Achievements mods enabler sse
Cutting room floor

Alternate start life (This gives you multiple roleplay options/scenarios)
OR
Realm of Lorkhan - Custom Alternate Start - Choose your own adventure
(You can choose personal attributes and starting stats this way)

In Game UI:

A quality world map  (make sure you disable map.swf in the skyui advanced settings)

WITH

Dear Diary - Journal Inventory MCM Paper Interface
ElSopa - Animated Celtic Icons For SkyUI SE
OR
Pastel Map Markers (if you wont use Dear Diary Markers)

AMatterofTime
FISS SSE
Skyhud (with the new patch)
Widget mod
Custom UI Replacer


Main Menu/Loading screens:

Immersive Old Map Main Menu Replacer
OR
Main Menu Spinning Skyrim Emblem
OR
Simple Perfection Main Menu Background and Music Replacer(plus Add
your own)
WITH
Ultimate Lore Loading Screen
WITH
(Optional) Replace Main Menu and Loading Screen Fog With Snow SE






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Audio:

Unofficial High Definition Audio Project

Lucidity Sound FX SSE

Audio Overhaul for Skyrim SE

Immersive Sounds - Compendium   (w/ Patches)

illy's High Quality Fire Audio - SE Edition

Musical Lore (Soundtrack Mod By Nir Shor)

Additional Music Project

Fantasy Soundtrack Project SE

Main menu music replacer Main Themes Combined ES 3 - 6 

OR

Main Menu music The Elder Scrolls Complete Mashup By Riftley (Honestly this one is more epic)








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TK Dodge SE

NPC's Run and Walk at Your Pace

Even Better Quest Objectives

Immersive Patrols SE

Ultimate Combat SE

TK Recoil SE

TK HitStop SE

Pumping Iron - Dynamic Muscle Growth

Ordinator - Perks of Skyrim

Apocalypse - Magic of Skyrim

Carriage and Ferry Travel Overhaul

Lanterns of Skyrim SE

Bring Out Your Dead

Hold Border Banners

Point The Way

YOT - Your Own Thoughts SE

Wintersun - Faiths of Skyrim

True Armor SE

Immersive World Encounters SE

Wildcat - Combat of Skyrim

Skyrim Reputation

Immersive Movement

Sit Anywhere

Know Your Enemy - Trait-based resistances

Wearable Lanterns

Guard Dialogue Overhaul Redux

Athletik Combat - Realistic Movement and Dodging

Bandolier - Bags and Pouches Classic