I would also like to know if it's possible to create patches from scratch.
There's NTR to do it, but I think it would be good to see other method to patch games.
Not learning how to create patches from scratch to patch games because it can already be done with NTR is not how we should act.
Exploring and understanding how everything work is what hackers want, not just sticking to what's already possible and giving up on other things.
Creating patches could be useful for Translation team, or releasing custom maps for games, etc.
Not everyone are using NTR cfw, some users already have EmuNAND and don't want to setup another one or multiple on the same card.
Providing choices to users is always better. NTR patches, cia patches, etc.