Most important is not a autokeypusher as Mcdan says... the most important thing is an Auto clicker.
Look, if u use full screen, and put yer mouse cursor to the side of screen, the screen will start rotating, right? Will if u r auto clicking left clikc.... yer char will start running in circles... thats the point of it.
If u do that in an area with big respawn and agressive mobs.... evetually (always very fast) u will be clicking on mobs... if yer zoom is adjusted to the point where yer chars runs in circles, small circles, the mobs that will come near you will be clicked.... and if there are many mobs, you will click each mob one time as the screen rotates. Then if u have a macro for pushing skills or some weight on keyboard.... you will attack each mob with one skill, while the screen is rotating and targeting a new mob.... so mobs will get hit one time, then the other, then the other, and back to the starting mob.... dont know how to explain it better.
Wait for thread starter video tutorial. Or just try it out.. if doesnt work, stop.... think for 3 minutes, and then re try. I dont know if i am doing it exaclty as thread starter stated it. But in my own variation of this technique it is working...
I use camara angle not in top of char.... in 45 degrees.... cause while rotating camara, that angle allows u to clikc mobs easier... with camara on top of char u need the mob to be extremly close for a succesfull targeting......
And with my nostromo n52... i configre more macros, to use buffs, pick up anything that mobs drops, and zoom in and zoom out of camara fast.... because sometimes in 45 degreee angle camara when u reach a wall the rotating stops.... so by zooming in and out very fast, it makes it continue rotating and no stuck anymore..
I am terrible sry for my rusted english, my main language is spanish.
Have a good day.