Phenotype Identification for the Vets

So i've said it before and i'll say it again, i've been around a million and one grows but all clones and i just had another realization. I am starting from seeds and am going to be going into a perpetual grow meaning that i'll want to make some mothers. What I have germinating right now is Sensi NL#5xHaze, Big Buddha cheese and Dina Sweet deep grapefruit. Out of these how and when do i select the proper pheno's for my mothers? I can def ask this down the road with pics a couple of weeks into veg but i just kind of want to be prepared.

you also want to weed out shity plants like realy slow growth