[TUTORIAL] Quick and Effective Way to breed a Team

[Srcsqwrn]

What is a good way to get a 6IV Ditto? I've been looking around, searching, but I mostly see people just trying to get one.
Is trading the only way?

I feel very unfortunate, because I've worked on an Aegislash I thought was decent, but I don't think it had perfect IVs.
I don't think I should make any new Pokemon until I get a 6IV Ditto, now.