Hello everyone, this is an "advanced" method that requires a sort of RNG abusing, but it can be pretty useful and can accelerate the first steps towards getting a 4/5 IV'd pokémon.
TIME MACHINE METHOD:
The steps to use this method is as follows:
1)Check the IV's of a pair of pokémon, it's recommended to use magikarps, since they're some of the fastest to lay and hatch eggs in the game, also they're easy to find and catch (Route 3 w/ old rod).
*TIPS: >Use neutral natured ones or the checking could be a bit tricky. >Use reset bags if your magikarps have EV's.
You can check their stats in Lumiose city in the Battle Institute (North), to get there, fly to the northern part of Lumiose and travel to the right, after passing the door to route 16, there it is, we'll use this since in this place, your Pokémon are set to lv. 50.
Save before entering, that way you can soft reset and use the other parent, since same species aren't allowed in the facility.
Write down the stats, for example mine are
2)Now fly to they day care and leave the checked parents there, give one a destiny knot and the other an everstone, keep in mind in what slot you've left them, now walk until you see that they've laid an egg, refuse the first egg, after refusing it, save (from now on, this will be our fixed point in time.
3)After saving walk until you see a second egg, accept the second egg, and hatch it, then you can check the newborn's stats in the Battle Institute in Lumiose city, that way you can see which parent passed down which stat, for example mine was:
HP 80 (Given by the Father)
Atk 20 (Random IV)
Def 66 (Given by the Father)
SpA 24 (Given by the Father)
SpD 26 (Given by the Mother)
Spe 108 (Given by the Mother)
4)Now you know which parent passed down which IV, so reset and you should be out of the day care, take the magikarps out of the day care and put anyone you'd like, in this example I used a Rotom with perfect IV's in HP Atk and Def as the father, and a Ditto with perfect IV's in SpD and Spe, that way I got a Rotom with the spread 31/x/31/x/31/31 with only one egg.
You can check the IV's in Kiloude city, also you can read my other breeding guide.