This pack was designed to ease developing new modpacks on 1.12.2 by containing the standard performance and QOL found in every pack. It is intentionally light, so you can add content mods as you see fit.
The modlist is small so that it won't potentially conflict with other mods in a modpack.
Modlist:
AppleSkin - Adds food values to food tooptips, and adds the saturation bar overlay.
Bad Wither No Cookie - Converts Wither and Ender Dragon sounds to be local instead of serverwide.
Better Advancements - Improves advancements UI to be larger and respect GUI scale.
CensoredASM - Massively optimizes code and RAM usage.
Controlling - Adds a search bar to the keybinds menu.
CraftTweaker - Allows modpack developers to add custom recipes, amongst many other things.
Dan's Crafting Tweaks - Adds hotkeys and buttons for the crafting table.
Dan's Mouse Tweaks - Improves how items are moved in an inventory.
DupeFix Project - Fixes a myriad of dupe exploits present in other mods.
Dynamic View - Stabilises the TPS by dynamically adjusting the render distance, within configured limits.
Enchantment Descriptions - Adds a tooltip for enchanted books and many modded enchanted books.
Fixeroo - Clumps together experience orbs. Unlike Clumps, it doesn't add a new entity.
FoamFix - Improves performance via targetted optimizations.
FPS Reducer - Save system resources by lowering FPS when the window is unfocused or left AFK.
Had Enough Items - Fork of JEI to improve memory usage and performance.
Just Enough Resources - Adds mod drops, loot tables, and ore spawns to JEI.
MixinBooter - Library mod for CensoredASM, Hesperus, Nothirium, and Universal Tweaks.
Mod Name Tooltip - Adds the mod the item is from to the tooltip.
Multithreaded Noise - Improves overworld generation by multithreading the noise generators.
NetherPortal Fix - Improves the accuracy of nether portals.
Nothirium - Optimizes chunk rendering to greatly improve performance. Incompatible with Little Tiles and a few other mods.
Particle Culling - Culls particles that are out of sight.
ReAuth - Allows players to revalidate their account if their session expires.
RenderLib - Dependency of Nothirium
Sledgehammer - Patches issues in Minecraft and other mods.
Spark - Adds a performance profiler command.
Universal Tweaks - Fixes a huge amount of bugs, adds powerful tweaking options.
燐/Hesperus - Fork of Phosphor, optimizes the lighting engine.
Suggested additional mods:
Aqua Acrobatics - Backports 1.13 swimming and crawling to 1.12.2
Attribute Fix - Fixes many mods and removes vanilla limitations on stats.
Bansōkō - Allows patching a mod's jar to change the code.
Broken Wings - Disables flight in specific dimensions.
Carry On - Players can carry tile-entities or mobs by shift-right clicking.
Client Tweaks - Adds many miscellaneous QOL tweaks.
CoFH World - Provides customizable ore generation, defined in a JSON file.
ConnectedTexturesMod - Allows mods to add blocks with connected textures.
ContentTweaker - Addon for CraftTweaker for creating custom items, fluids, and blocks.
Copy-Paste - Adds a folder where files will be injected into saves. Applies on both world creation and world load.
Corpse Complex - Adds control over what happens to a player's inventory, xp, and hunger when they die.
Cosmetic Armor - Allows players to wear a second set of armor which overrides the texture of the first.
CraftTweaker Integration - Provides additional functions for CraftTweaker.
CraftTweaker Utils - Provides some more functions for CraftTweaker.
Custom Backgrounds - Changes the dirt background in menus to a list of textures.
Default Options - Ship configuration with the modpack. Highly recommended, especially for reducing keybind overlap.
Default World Generator - Allows pack devs to specify world generation presets.
DiscordRichPresence - Adds modpack information to the Discord status.
Dropt - Allows modification of block drops.
Equipment Tooltips - Adds information to tooltips about mining level, damage, armor etc.
Fancy Menu - Allows creating a custom main menu.
FindMe - Press a keybind to find an item inside any nearby inventories.
FX Control - Gives full control over player effects based on defined conditions. Highly customizable.
Game Stages - Players can be assigned "stages", which can unlock using items, crafting recipes etc.
HungerTweaker - Exposes AppleCore API to CraftTweaker.
Hunger Overhaul - Hunger can deplete at a configurable rate, amongst other settings.
HWYLA - An alternative mod which shows the block you are looking at, has additional features with Jade, WAILA Harvestability and WAWLA.
In Control! - Allows configurable mob spawns.
InWorldCrafting - Provides capabilities in CraftTweaker for crafting using items and fluids.
It's the little things - Allows customizable window titles, icons, warning screens, server lists and welcome screens.
JAOPCA - Dynamically generates items and recipes to provide ore-processing copatibility, JAOPCACustom allows defining custom items.
JEI Utilities - Adds more features to HEI, such as a recipe history and improved bookmarks.
JourneyMap - Generates a map of the area around a player.
Just Enough Calculation - Adds a calculator for maths, and a crafitng calculator for recipe costs.
JETIF - Shows recipes in HEI which include fluids, such as EXU2's demon ingots.
KleeSlabs - Break only half of a slab at a time.
Malek's Infinity Gauntlet - Prevents specified items, fluids, potions, enchantments etc from being registered, decreasing load time.
Mantle - Changes the color of hearts depending on how many rows you have.
Material Changer - Allows changing properties of weapons, tools, or armor.
Modpack Configuration Checker - Adds some utility features, like opening URLs as the game launches or checking if the assigned RAM is enough.
Mod Pack Update Checker - Checks a URL to see if the modpack is up-to-date, and displays a configurable notification.
ModTweaker - Provides capabilities for CraftTweaker to modify recipes from many mods.
MoreTweaker - Provides capabilities for CraftTweaker to modify recipes from more mods.
MPUtils - Suite of mods which add useful packdev commands, add an issue tracker or changelog, or display tips after a trigger.
Neat - Shows a mob's health in a bar over their head.
Ore Excavation - Players can vein mine blocks. Can be restricted to an enchantment or Tinkers modifier with Ore Excavation Integration.
Overloaded Armor Bar - The armor bar changes color if modded armor provides too much for the vanilla bar.
Proportional Destruction Particles - Makes destruction particles fit the collision box instead of taking up the whole block.
Requious Frakto - Provides custom machines, and notably custom HEI pages.
Resource Loader - Can override a mods texture without using a resource pack. Dependency for some mods.
Rocky Tweaks - Provides capabilities for CraftTweaker to modify anvil and villager recipes.
Stuff A Sock In It - Adds configurable filters to remove useless lines from the log file.
The One Probe - Shows the block you are looking at, more features with TOP Addons and TOP Extras.
Tips - Shows customizable tips on loading screens.
Tomb Many Graves 2 - Creates a grave with the player's items inside when they die.
Tool Progression - Allows modifying the mining level of tools and blocks.
Twerk Sim 2K16 - Grow plants faster by shifting. Mostly useful for skyblocks.
Unidict - Tries to simplify all of the same resource into 1 e.g. copper ingots. Works with InstantUnify to ensure complete unification.
Zen Utils - Adds more features to CraftTweaker.
Performance mods have been taken from here.