well it depends on what your goals are man, for me, I clone/veg for about the same time it takes to flower, so my plants are a lil big. but I train to four colas or six depending on the strain.
match the canopy of the plant to the container size, and that way they all fit perfectly.
to maximize your grow yields you need to take time into consideration, as you cant move IN more plants if the flowering ones aren't done.
so the 70 days or so that I flower, is the time I take to clone, train, and vege.
but if you have three rooms instead of two, you can do all sorts of cool shit.
but I don't I have two rooms/sheds.