depending on how you make them and what you consider feminized they are actually not that difficult to make, If you have 2 female plants you make 1 turn hermie and save her pollen and then grab the other one and knock her up. the seeds will all be female or hermie(not as in all will be female or all will hermie). the other method is more difficult though, but its not too hard either. you take a bunch of females and give them an hour of light during the dark period for a few weeks until you find a true female(a female that can not hermie) then use colidial silver to make it grow balls and use that pollen.