oldsanclem's method is also called 'cloning for sex' and is the way that experienced and efficient growers operate.

You can also do this:
Cut clones from seed plants
When the clones root, put the CLONES in flower in small pots.
When the males show, throw away all the male clones AND the donor plant they came off.
You are now left with all females.
You can take some more clones now, again numbering them according to which seed plant they came from.
At harvest time, determine which of the clones performed the best in terms of yield and quality.
Put all the OTHER donor plants into flower except for the really nice one, and all the clones you just took. This is your second crop, and will be the last one where you see significant variation.
Save the nicest one to be your permanent mother, and take another round of cuttings from her for your third and subsequent crops.