To do it right, and have the best probability of producing the best f2s you possibly can, ---You would want to grow out all of the seed plants.
-Discard any stunted, mutated, slow growing, or unworthy plants. Only the best should remain.
-Take cuts of the remaining plants.
- You can keep your clones in stasis or root and veg them while you Flower out your female seed plants..
-After drying and curing test your females. Whichever flowers exhibit the best traits, you will keep. There may be 2 or more females you decide to keep. Pitch the other female clones.
From the remaining females you will need a few clones of each pheno rooted. However many males you need to test, you will need that many cuts of each female phenotype.
Now breed each male to each different female, carefully labeling each cross. (EX. Male #1 x Female #1, theres many different ways ppl chart and label, whatever technique u use)
You will grow out the resulting seed from each cross and the final product tested. This is the only true way to test males, and their compatibility. Any other method is a shot in the dark. Eventually you will end up with one stud, and the best female from your pack. You can go on with these up the filial gens, or even bx.
A shorter method would be open pollination. All seed plants would be grown out in the same space and vegged for set amount of time. Any spindly or weak plants discarded of course. You would flower the males and females together, and just let the pollen fly. After drying select only the best buds, to save seed from, discard the rest. You could then go into testing the resulting seed, and only breeding with the best plants. Over several seasons selecting for your favorite traits. You wouldnt know who the best male donor was in this case, but Ive seen it done both ways. If your serious about breeding I would test each male. If you just want a good seed stash, open pollinate.
Many ppl claim to have their techniques for selecting the best males during veg, but theres no true way to know what traits a male will pass or what will be dominant, unless you actually complete the cross, document and save everything. A lot of ppl think breeding is like mixing paint. When in fact its much more complicated. Whatever you choose to do I wish you the best of luck, and theres loads of information about plant breeding, more than I have time to get into right now. Search around, theres tid bits here on this thread, other forums, and other parts of the web. If your thinking about getting serious with plant breeding I would suggest finding a Robert Clarke book