This document will only cover glitches and skips that are relevant for and useful in a speedrun, either Any% or NG+. Please contact me (Nysyarc) if you have discovered a useful glitch or skip and I will add it to this document and give you credit.
Goblin Skip - Discovered by: Nysyarc (April 28th, 2020) - Can be performed on both console and emulator
In the Caradhras: Moria Gate map area (the area just before you enter Moria and split for Caradhras), you can avoid the trigger that spawns the goblins in the top half of the area. The trigger exists just below the rocky path that crosses the river at the left side of the map. To avoid it, simply hug the river (walk directly alongside it as closely as possible) to the right of the crossing without moving downwards at all.
This works and is viable for Aragorn, Legolas and Gandalf in both Any% and NG+. It will skip a brief cutscene of the goblins talking, as well as having to fight or move past the goblins. Unfortunately, while the skip works for Frodo, it also results in a broken cutscene and a soft lock when exiting the area, so it can't be done in either of his categories.
Legolas Overdraw Glitch - Discovered by: Basically anyone who played casually - Can be performed on both console and emulator
As Legolas, simply press A to use Overdraw while you are moving (NOT while standing still) to fire the arrow in the direction of your movement and avoid the charging animation. You should never be using Overdraw while standing still in a speedrun.
Black Gate Skip - Discovered by: Nysyarc (April 12th, 2020) - Can be performed on both console and emulator
As Frodo, in the North Mordor: Black Gate map area (the third map area in North Morder, after the Dead Marshes), it is possible to exit the area earlier than intended by hitting the exit loading zone from a cliff below the main road. After the main road turns upwards toward the black gate, follow it until you see what looks like a tipped over barrel above it, and go up and to the right above the cliff to the right of the barrel. You will pass a Forge, and a breakable wooden barrel to the right of the Forge. You can hit the loading zone by walking just to the right of the barrel.
On top of simply being a shorter route to the exit and avoiding several orcs, this will also skip some dialogue with Sam and Gollum, and is useful in both Any% and NG+ to save time.