Alright, I want to start training my team competitively.

I already beated the Elite 4 with a fully Super Trained team but that's not enough, it seems I have to breed a shitton of eggs to, someday, have mons with perfect IV.

So, how do you do it?
You go to Friend Safari and catch some Dittos?
I breed them with my current team which already has the natures I need?

I know all about EV, but I'm a noob at IV's.