Well, you gotta be DIVERSE with breeding, get the pokemon you wanna breed, and breed a bunch of them.
Breeding naturally produces higher stats than catching, from there, you just breed until you get the stat you want. Once you got 2 pokemon with 31's in one or more stats, you give them the power item that transfers that stat to the baby pokemon, 2 guaranteed 31's, and the last 4 are random, I'm lucky enough, so I usually get 2 MORE 31's, and then 2 really low ones...