I usually breed for perfect IVs, usually sweepers like Garchomp and some of the "Overused"-tier Pokemon, with certain conditions like minimum IV total being 131 and not one IV must be below 5 or 10, except maybe for one "useless" stat (such as Sp.Atk. for Weavile or Attack for Blissey/Serene Grace Togekiss)
Currently, I'm having 6 Jolly Gibles with x/31/x/x/x/31 IVs, not to mention I also have 4 at my Diamond cart.
And EV-training too, 252 Speed & Attack/Sp.Atk. for sweepers at the Victory Road ponds, where after I infect the ones to be EV-trained with pokerus, I feed them 10 Proteins/Calciums, then I attach them with power bracer/lens, and let them gain not just EXP points but also boosted EVs from the Golbats defeated by my switch-in high-leveled Steel/Poison-type Pokemon with leftovers (to avoid poisoning from poison fang). I do that 19 times, because...
100 + 19*2*4 = 252 in Attack/Sp.Atk EVs.
The 2 is the boost from pokerus, and the 4 is from the power items.
and 100 + 19*2*2 speed EVs from Golbat = 176 Speed EVs.
Then attach power anklet to the pokemon, and defeat the Golbats 6 times...
176 + 6*2*(4+2) = 248 Speed EVs.
You get 4 EVs plus 2 EVs from defeating Golbat, and that makes 6, then multiply it with 2 for the pokerus boost, and 6 for defeating 6 of them, which is 72.
And remove the power anklet, then defeat just one more Golbat to gain 4 more EVs.
248 + 2*2 = 252 Speed IVs
Add the remaining to the rest of the stats, like HP. Self-explanatory
This works only for the 252/252/6 EV spread. And this is the quickest way to EV-train for that spread (don't forget the pokerus).
I guess some of you also do this process of EV-training.
And while I do that, I also bring along 1 or 2 Level 91 Pickup Linoones, to pick up rare stuff like dawn/dusk/shiny stones, rare candies, pp ups, etc.
Oops, I made my post too long