Get enough sleep.
That's preparation.
Knowing how many points of information to give to the questions is something that falls under exam technique.
Knowing how to deal with the layout of the exam is exam technique, I'd even say dealing with 3 essays for english falls under this.
Knowing the specific terms needed for definitions - those key words... that's probably exam technique as well.
Structuring your questions clearly to what is asked is also exam technique.
It really has to do with all those things you need to do well that aren't to do with how much of the course you know, and how healthy you are. The best way to prepare for it is usually just doing the exams, and looking at examiner reports. However, with a new study design it sometimes may be helpful to actually talk to examiners etc.
But yeah, IMO it definitely is a thing, and it definitely is important. At least for theory subjects.