In my 21 kill game, it came down to the pure luck of being able to kill the last 12 people left in the game by myself.
You just have to luck into a situation where the enemy teams aren't actually fighting each other and you just happen to walk into all of them. The combination of luck and having the skill to actually win those fights, anyway.
A lot of the elements are outside of your direct control, though.
I hear it's easier on PC because players are more confrontational/reliant on their gunskill. Frothy was talking about this in one of his vids, saying how in some ways it's actually harder on console because they focus more on strategies which slow gameplay down. Doing things like running away to get a different angle, instead of pushing and relying on their gunskill, for instance.