To get a Pokemon with near perfect IVs you should have the following things:
- Patience, a lot of patience
- 30 repeat balls
- A Pokemon with synchronize as ability
Most essential (Main answer)
To get the IV's that you want, you should catch 4 ditto with a beneficial nature and a desired IV(you can test this in black 2. A ace trainer will tell you the potential of your Pokemon.It is best that all de 4 ditto have a different max IV.) To make sure you catch 4 ditto with a different nature and IV potential, you should catch thirty ditto with a magikarp leading in your party. When the ditto transforms into magikarp it will have a 100% catch rate. Now switch it out and send in a Pokemon with synchronize as ability. Catch the ditto. Do this thirty times ,until all your repeat balls are finished. Now choose 4 ditto that have the beneficial nature and the good IV potential that you want on your Pokemon. Breed the first ditto with the male species of your desired Pokemon. The hatched egg will have a flawless IV. Breed the newly-hatched Pokemon with the 2nd ditto. Keep doing this until you have a male Pokemon with both the IV's you are passing down.This male Pokemon also has the potential to be the father of a flawless IVd Pokemon.
Breed a ditto that has the third desired IV with the father.Keep hatching eggs until you get a Pokemon with the third desired IV and also (preferably) one of the two IV stats of the father. Breed a ditto with the desired nature that is holding an Everstone with the newly-hatched Pokemon.Keep hatching eggs until you get a female Pokemon with the desired nature and the third IV. It will be best that she has one of the two IV the father has. She will be the mother of your flawless Pokemon and is very essential.
Now you are getting close to getting your flawless Pokemon. Give the mother an Everstone and let her breed with the father. Keep doing this(this usually doesn't take long) until you have the Pokemon that you want. If everything is done correctly you will have a Pokemon with flawless IVs.
This is a nice method you can use to breed a perfect IV trained Pokemon, however