In a number of ways: Breeding would be easier, just longer. Basically, just common sense and not ignoring any part, while doing your research on everything. IV doesn't matter, unless it's Gen III/IV origin, in which case. yet, but may need it set on something other than the default) Shiny legality (for those that can't be) Egg data is basically: Set to Day Care Couple (location you got the egg itself). ORIGIN DATA MATTERS (Game obtained in, at what level, where in-game it was caught/hatched, what Balls it can be obtained in, etc). Check if your Hidden Ability is legally available Research your legal Moves (especially if you want a move that is only available in a past generation, this can get icky thanks to origin data and PID) If from gen V, then some more homework is needed, and if from Gen III/IV, then a fair bit may be needed, such as learning PID rules.

As far as the actual question of Genning Legal Pokemon, that's not too hard, assuming you are making them hatched/caught in Gen VI.

Genning pokemon on mac