Mods to Avoid

This list is far from comprehensive. There are still tons of mods not listed here that will break your game. This is why it is very important to have some modding knowledge before adding any mods.
Always view every plugin you install with SSEEdit to check for conflicts.

Oversized textures
Based on the object size and how the texture is wrapped around it, you should pick textures with a reasonable resolution and avoid the very big ones also based on your display resolution. Keep in mind that the textures will not be displayed with their full resolution at all times, in fact they will be scaled down because of mipmaps based on distance and other factors, as shown with these sliders. Just for reference, a maximum of 2K at 1080p is a pretty safe bet in terms of balance.

AI-upscaled texture packs
Mods upscaled with AI or other lazy techniques generally are not worth the higher VRAM usage.

Any mods that edit timescale
Vanilla AI packages and scripts are based on the vanilla timescale, and can break and/or run when they aren't supposed to if the timescale is changed.

Sinitar's Modlists
If you have a few hours and want more information about Sinitar's lies, scamming and lack of modding knowledge, check out this twenty-eight page essay that goes into excruciating detail about it.

ENBoost
Completely unnecessary on Skyrim SE and unsupported.

Fores New Idles
Unsupported and dated, lots of new animation mods will not work with this. Use Nemesis instead.

Achievements Mods Enabler
Achievements are already enabled by Engine Fixes.

HDT-SMP
Completely replaced and superseded Faster HDT-SMP.

Breezehome (by Elianora)
Has lots of errors and deleted navmeshes that will cause crashing, do not use without this patch.

Parallax
Any mod applying parallax on meshes will have to replace them, often reverting important fixes. Not easy to manage for beginners and they are not worth the visual improvement since a properly made normal map can still look good. Terrain parallax is way easier to manage and will not cause issues, you can safely add it on top of this guide.

A Matter of Time
Has a broken plugin that contains HITME records. Resave in the Creation Kit for a fix, support will not be provided.

LOD billboards and pre-generated terrain LOD
DynDOLOD 3 generates object and tree LOD that will actually match your modlist with far better results than what resources can provide.
SSELODGen generates configurable terrain LOD.

SSE Fixes
Mostly replaced by Engine Fixes, the only thing missing is the mutex fix, which you realistically only benefit from if you have a very large amount of plugins, way past what the guide has. If you do want to use this mod, then disable all of it's functions in the configuration file except for the mutex fix.

Summerset Isle
Horribly made mod.