What I usually do is I start a breeding project by obtaining a female in Friend Safari (if possible). Then I'll breed it with a Ditto of the correct nature/father that has egg moves I want until I get a female (any IV) that has the right nature and egg moves. Once I have a female with the correct nature and egg moves, I'll breed it with my highest IV father in the egg group (at this point, I have flawless 6-IVs for most of them, but at least a 5-IV in all) until I get a better female. Then I'll breed the better female with the highest IV father. Rinse, dry, repeat. Eventually you'll get your desired result.Ah, but if I want to use my pre-existing 5iv parent(no other better parent atm) of one species to breed with another species, then I'll just have to deal with it, isnt it? Or, in your opinion, is it easier to just restart from the safari(3ivs) and start my way back to the top to get the 5iv parents?
So, long story short, it's WAYYYY faster to just put up with the slow egg production, but have to hatch less eggs overall, then it is to start from scratch with each new breeding project.