When it comes to "the mental aspect of the fight" think simple concepts.....not numerous techniques. Then apply common sense.
Position in the reactionary curve
Known Variables, who are you?
The rest of the situation....."the fight will be what the fight will be."
Get "the mental aspect of the fight" down and then train in what allows you to be the very best that you can be inside of the correct context of the fight.
This is going to require fluidity.
"Be like water."