Fair, strategic and varied combat: No health sponges or infinite magicka for NPCs. Enemies have strengths and weaknesses to strategize around.

Meaningful progression: The player starts off weak: wolves are dangerous, wearing armor is tiring, learning spells is an ordeal and many dungeons will be off limits. Nonetheless, as you level up, your character will meet these challenges and by the late game you'll be facing down dragons in single combat. The path to godhood is long though, with your character steadily building in strength across an expanded early- and mid-game.

Immersive exploration: The compass and map are much less useful, instead you actually need to think about where you are going. Landmarks, roadsigns, guidebooks and clairvoyance will all help you on your way.

Grind-Free Leveling: Skills are no longer leveled through use, so there's no need to grind them. Instead, you level your character and skills through a gold-based system. But there's no grinding for gold either because carry capacity and the value of basic crafted items is reduced. Instead gold rewards from quests and loot are increased, encouraging non-crafting builds to actually get out there and explore.

Highly modular: All of the mods below are 100% compatible with each other and so can be dropped if you don't like them.





Programs
zEdit or Synthesis - Enemy Releveler, NPC Stat Rescaler

Frameworks
Address library for SKSE plugins - Acolyte, Blade & Blunt, Challenging Spell Learning, Experience, Know Your Enemy 2, Locational Encounter Zones, Static Skill Leveling Rewritten, Tribute.
Don't Eat Spell Tomes - Challenging Spell Learning
Keyword Item Distributor - Know Your Enemy 2, Master of One.
MCM Helper - Static Skill Leveling Rewritten.
SKSE - Acolyte, Challenging Spell Learning, Cobb Encumbrance, Curse of the Firmament, Economy Overhaul and Speechcraft Improvements, Exhaustion, Experience, Know Your Enemy 2, Legacy, Master of One, Sidequests of Skyrim, SkyUI, Static Skill Leveling Rewritten, Tribute.
SkyUI - Acolyte, Challenging Spell Learning, Curse of the Firmament, Economy Overhaul and Speechcraft Improvements, Exhaustion, Legacy, Know Your Enemy 2, Master of One, Tribute.
Spell Perk Item Distributor - Acolyte, Blade & Blunt, Know Your Enemy 2, Master of One.
PowerOfThree's Papyrus Extender - Sidequests of Skyrim, Static Skill Leveling Rewritten.

Bug Fixes
Attack Speed Framework (or another mod that fixes the attack speed bug) - Master of One.
Dual Casting Fix - Blade & Blunt.
PowerOfThree's tweaks - Acolyte, Sidequests of Skyrim, Static Skill Leveling Rewritten.
Scrambled Bugs - Blade & Blunt, Master of One.
USSEP - Economy Overhaul and Speechcraft Improvements.

Master of One

Vanilla perks are just part of general character progression; you always want perks in the skills you use because they are all good. Master of One changes this by adding more niche perks and giving all perks drawbacks as well as benefits. Now you need to actually consider which perks will benefit your build and which should be avoided. The perks also have multiple ranks allowing you to customize the extent to which you invest in a particular trait. The end result is that you can push your character to extreme specialization, facilitating a range of unique builds, but in all cases you will have weaknesses you will need to prepare for.

Curse of the Firmament
Vanilla standing stone blessings are bland, minor buffs that do little to differentiate your character. Curse of the Firmament makes the effects much more pronounced and gives them all negatives as well as positives. This makes choosing a stone much more risky but also makes each one feel unique.

Legacy - A Race Overhaul
A race overhaul that gives all races strengths and weaknesses that impact gameplay and affect the player and NPC alike. The effects are more complex than vanilla or Aetherius, but not as involved as Imperious.

Acolyte - Divine Covenants
In vanilla religion and worship is forgettable - bland effects and annoying trips to shrines. This mod gives devotees exotic god-like powers, but only if they can prove their faith by bearing a sizable penalty while their devotion steadily grows. Given the penalties, you should pick a divinity carefully.



Know your enemy 2 AND Know your enemy 2 - armors AND their Integration patch
These give enemies a wider variety of resistances and weaknesses, contingent both on their race, but also the armor they wear (player armor is affected too). You might want to think about what equipment to bring before you enter a dungeon, and single-skill builds are much less viable. You will need to vary your strategy contingent on the enemy you face.

Blade and Blunt
A top quality combat overhaul that improves AI, mechanics, weapon reach and turning speed, all while remaining true to vanilla. Critically it makes stamina management more important during combat and so adds another layer of strategy.

NPC Stat Rescaler
** Don't run patchers yet **
Vanilla enemies have enormous health pools, particularly at high levels, and they also have grotesque magicka regen speeds that mean you can never wear them down. The NPC Stat rescaler changes this, giving enemies more realistic health pools and magicka regen rates. This makes combat more about skill and strategy, and less of a war of attrition.

Exhaustion
An ultra-lightweight injury mod. As you deplete health, magicka and stamina you accrue exhaustion which slows your natural regeneration until you sleep it off. You'll want to find places to rest and recover and plan for long trips. As your character grows you can use perks and gear to buff your regen making you "exhaustion proof" and contributing to a sense of progress.



Challenging Spell Learning
In vanilla anyone can learn any spell provided they have the tome. This mod turns spell learning into a trial of your magical abilities. Now non-magical characters will struggle to learn any but the most basic spells and so won’t have a fall back arsenal of spells if they get into trouble. Meanwhile high level spells require investment, creating more pronounced differences between different magical builds.

Geometric Stat Growth
Vanilla's +10 h/m/s on level up powers you through the early game, and you quickly settle in the late game. Geometric Stat Growth spreads player growth more evenly across levels, drawing out the early and mid-game, while making even late game level ups meaningful.

SRLEZ
De-levels dungeons, such that player level does not affect the enemies or loot inside. Instead, dungeon size and enemy type is key. A small bandit den might be a trifling matter, but a large draugr tomb is formidable. You’ll need to work and level up before thinking about entering a high level dungeon which draws out the early game where you’re a “nobody”, but makes the mid and later game more rewarding. Nonetheless, thanks to the NPC stat rescaler, high level enemies aren’t total sponges, so with good preparation a low-level player may be able to make their way through a challenging dungeon.

Locational Encounter Zones
In vanilla, dungeon exteriors are all part of a global level 1 encounter zone, this means entrance guards can be misleadingly easy for tough dungeons. This mod links dungeon exteriors to their interior encounter zone for a more consistent experience. 

Enemy Releveler
** Don't run patchers yet **
Even when encounter zones are deleveled, the enemies themselves have very wide level ranges that just confuses the experience of fighting them. The releveler fixes this making different enemy types much more distinct. Bandits are now consistently easy, draugr consistently tough, dragons and vampires consistently dangerous. As your character grows in strength they will be able to handle new enemy types.

Missives and Sidequests of Skyrim
These let you complete oddjobs for townsfolk. Handy for extremely low level characters who are not yet ready for even minor adventuring.

No Saving in Combat
No enemy is hard if you can save-scum. By stopping that you must ask yourself “do I really want to risk this?”. Now you have a real incentive to go into dungeons well prepared and to stay away from high level areas until you are ready.



Undiscovered means Unknown - extreme compass
** Install the extreme compass edition (new), I suggest turning off undiscovered location icons entirely, as well as enemy indicators **
Your compass no longer magically tells you when locations are nearby. This encourages you to look at the world and you’ll start noticing all the small cues that guide the player - a dirt track, or little cairns, or some trampled snow. Finding locations is a little more difficult, but much more rewarding: you can now stumble across an ancient ruin without the reveal being spoiled by your compass.

Point the way
This mod helps you keep on track without opening your map every 20 seconds.

iHud
Hide the compass when not needed. I also recommend turning off enemy health bars, it makes each fight more uncertain and nerve-wracking.

Ambiance
By making dungeons darker, lighting mods forces you to make an important decision: stumble around in the dark, or use a light source and risk giving your location away. Vanilla dungeons are too bright to force this choice, Ambiance is my personal choice, though there are many other options.

Quick light
Darker dungeons require a light source, and vanilla Skyrim includes two options: torches or light spells. But these are a bit boring and frustrating: torches cannot be held while using 2H weapons or bows, so these characters have to fight in the dark, while magelight needs constantly recasting and cannot be dispelled. Quicklight solves this by giving you a toggleable lantern (hold E to turn on/off) that leaves your hands free and doesn’t need regularly topping up. This gets rid of the above frustrations, while leaving the strategic decision of whether or not to illuminate yourself in place.

Realistic AI Detection
In vanilla, your ability to sneak is hugely affected by your sneak skill, to the extent that a high level sneak character is borderline invisible. Realistic AI detection makes raw skill matter less, but lighting, movement and noise matter more, so placing more emphasis on what you do and when you do it, than who you are. It also plays nicely with Quicklight as it makes using a light source riskier than in vanilla.

Sightseer - Standing stones
Skyrim is full off cool places to visit, but no way to deliberately find them without quest markers or the internet. Sightseer provides in-game guidebooks to the standing stones, and a hidden quest too.

Pick Your Poison
The vanilla alchemy interface gives you no clues about where you need to go for specific ingredients, or what they look like, or what ingredients are useful for certain effects. This makes strategic foraging an impossibility. Pick Your Poison adds series of books that give you all this information.




Experience 
Grants character XP for quests and exploration. However, I suggest turning all sources of XP off as we'll be leveling up via...

Tribute 
Gives the player a power that converts gold into level ups though Experience's API.

The uncapper
Can be used to disables skill increases through use, thereby ending the need to grind skills. Instead we'll increase our skills with...

Static Skill Leveling Rewritten
Let's you pick which skills to increase after leveling up. Because you pick the skills you want, you can created highly unique characters. 

Economy overhaul and speechcraft improvements
** Install the lite version **
A total economy overhaul with an adjusted speech perk tree. Makes selling junk worthless and crafted items are hard to sell unless you are a good craftsman. Overall it makes it harder to get rich quick and encourages questing over spamming and hoarding. Stops you from grinding for gold to level up.

Cobb Encumbrance
Cobb Encumberance changes your movement speed according to how close you are to your weight limit which discourages hoarding. Investing in stamina, and so increasing your carry weight, has the nice effect of increasing your movement speed too. Again, its to discourage grinding for gold.





Put Ambiance.esp at the end of your load order, put USSEP at the top. Nothing else matters. There are minor disagreements between SRLEZ and Economy overhaul regarding some jewelry leveled lists, but they are of no consequence.

Tweaks

Both Blade and Blunt and Master of One apply stamina costs to drawing a bow. Together they are too much. Download the patch from the downloads here to remove Blade and Blunt's.

ini Files

Scrambled Bugs - set the following to true:
Quick Shot
Accumulating Magnitude
Improve Multiple Enchantment Effects
Leveled Characters
Perk Entry Points: Apply Multiple Spells
Poison Resistance
Power Attack Stamina
Reflect Damage

Blade & Blunt - set bEnableInjuries = false

Experience - set the following:
bEnableKilling = false
bEnableReading = false
bEnableSkillXP = false
fSkillCapBase = 100.000000
fSkillCapMult = 0.000000
bUseRacialCaps = false
bShowMessages = false
In the [Questing], [Exploring] and [Clearing] sections, set everything to 0.

The Uncapper - set the following:
bUsePCLevelSkillExpMults = false
bUseAttributesAtLevelUp = false
In the [SkillExpGainMults] section, set all skills to 0.

zEdit Patchers

Run them now:
NPC Stat Rescaler
Enemy releveler

MCMs

Static Skill Leveling - Choose how many skill points you get per level. I fix it to a flat 3 points, with all skill ups costing 1 point. This way I get a fixed 3 skill ups per level up.
Economy overhaul - I make selling prices a little better for the player at both low and high skill levels, otherwise I find money just too hard to come by.
iHUD - Hide the compass by default, I also turn off enemy healthbars.
Curse of the firmament - Choose yourself a starting stone (or multiple) if you wish
Sidequests of Skyrim - I disable the more dangerous requests to focus on minor errands.





Thanks to the authors of all the mods on this list. Thanks to everyone who helped me make my own mods. Thanks to u/Necromencer92 for the image used on this mod page.