Breed a strain with regular seeds and at the end create a fem version by reversing one female (from for examples your F5) to produce pollen and use that on another female. Or do what many breeders do and self a female... (selfing means getting pollen from the same female you drop it on).
im going to start a breeding project from a backcross of an f3 pinkie pie to an ak47 auto and ill be using fem pollen for each generation to see for myself if this creates any problems or just turns out to be a more efficient means of creating strains.
Started sexing my plants this week so far 15 plants from seed I got 7 or 8 females a few I'm waiting on. 50/50 ratios are common under minimal stress.
I took clones from 14 of them looking at 11 or 12 ladies going into flower end of month.