back crossing, take your male ( call him m)cross with your picked female( call her f) you have a FM hybrid.. grow out the FM seed select a female that best meets your requirements and breed this FM female back into your male clone witch is a b2, so this b2 hybrid is a ( MxFM) and is 75% M traits and 25% F, it can be done as many times you like, a b10 is 99.9% M trait..... hope this helps