IDK if what I am doing is correct or not, I have been doing lots of reading on breeding, genetics and the like the past few months both for the ladies and just plant breeding in general. The best way I have figured it is to select the strain you are looking for, say NL I then go into my seed search engine,
http://en.seedfinder.eu/index.php?SUCHE=SEEDS&GO=JA and I look up what made NL and there are lots of varieties from different breeders. So if you look at this chart given for seedsman's NL you find that if is from NL clone in 1985 and was crossed with Haze to form their version of NL (IBL).
So now you have your seeds lets say from seedsman you grow out several seeds say a 10 pack and for the sake of ease you come up with two phenos out of this since it is a F1 cross and normally you are only going to receive 4 phenos from an F1, but this line is already been bred back to itself over many years.
Ok so now you have two phenos and have both male and females of the same phenos. You pick the pair you want to breed to each other. When you cross these 2 say Pheno #1 with Pheno #1 and obtain the seeds from this cross, you have a new F1 with your Pheno #1 as your dominate traits. If you then cross these back with each other you will show many more phenos with this generation. Now if you back cross with your original batch of seeds, meaning that you have a clone from the original seeds from seedsman you are starting to stablize what your crossed.
This is a simple explaination with lots of drawbacks doing this on a small scale but also with the possible reward of having something unique and adapted in future generations to your own growing conditions. The major drawback is to breed to closely in your gene pool and lose the hybrid vigor you obtain with the crosses. I can't say that I have ever made a strain which I could breed true but I have been able to produce a majority of like plants with the vigor of new hybrids. I am still trying, still learning and still making seeds. I think the most important factor in doing this is record keeping and lots of notes and photos.
Presently I am starting a new program with seeds from Sannie's. I bought several strains which have common strains throughout and now trying to figure out which I want to try and set up for ILB and look for a promising F1 in the future.
Did this make any sense? Sorry if it didn't I still sit here with my breeding charts from the different strains and figure out what came from whom but sure am having fun doing it.
Best of Luck and Happy Growing