"The Jedi Path" book has some very interesting info on 'Marks of Contact' - basically the ways in which lightsaber combat is ended. Notable ones which we see in the films include:
Shiak, the second fundamental mark, pierces an opponent with the blade's point. Preferred for its precision, it is a Mark that indicates you are in control of the blade and the Force is in control of you
A pretty noble way for Maul to kill Qui-gon, all things considered.
Cho mai severs the weapon hand entirely, leaving your opponent alive but unable to continue the fight, and is thus a merciful conclusion to battle.
This is how both Anakin and Luke lose their hands, which does make sense in context - Dooku is a civilised duelist who also doesn't consider Anakin much of a threat, and Vader has just told Luke some very important information and is probably wanting him alive so he can turn. Also this book has annotations from varying owners, and this part is annotated by Luke with "I don't know that I'd call it merciful"
Sai cha is the act of cutting an enemy's head from his shoulders. It is never the intention of a Jedi to extinguish a fellow life, [...]. But when required, a lightsaber can also kill. If a shiak thrust through the heart cannot be done, this is the preferred method for a fatality.
So Anakin's killing of Dooku is relatively noble in its method, at least.
And now, we come to Obi-wan "forbidden methods of killing people" Kenobi!
Mou kei is a forbidden variant [of limb severing Marks], literally meaning "to dismember". It involves the act of cutting through several limbs at once. You should never need to use mou kei against a living being given the many alternatives.
Annotation from Obi-wan - "I can't see ever using such a Mark" š
Sai tok slices an entire body into two halves. The act is rightly considered barbaric and evidence of the furious emotions of the dark side. Unless you're fighting droids, no student of mine should ever use sai tok.
So yeah, Anakin 'war crimes' Skywalker learned it from somewhere. To be fair they make sense in context, since Obi-wan is left with very few options when fighting Anakin, and is very much angry and furious at Maul. However I have to assume the Council was not happy at Obi-wan for how he killed Maul lol