Matt made a tutorial for any% some time ago. It covers all the basics and the majority of it is still valid.

There have been a few updates to the route since then so I made a supplementary video. Ignore the strat I do for chapter 18 - it's outdated.

This is the newest version of chapter 18 skip. Instead of hanging off of the ledge like I do 15 seconds in, go onto the panel on the ground like you would casually and then restart checkpoint - you'll be able to jump straight away after you respawn.

Chapter 19 also has a skip for the second half of the section that wasn't covered in either of the previous guides.

As a note, the chapter 5-7 skip Matt covered in his video is not technically obsolete as Erims found a different way to get to chapter 7 quicker. Currently there are no guides for it but you can refer to French's clip for an idea of how it works.

Feel free to ask in the discord or forums if you have any questions :)