I'd start a good lst training when your plant has reached at least it's 4th - 5th node. The benefits are the same as as topping except that instead of stressing out your plant by cutting it you bend it over and trick it into thinking that something happened to it's main stem and that it needs to send energy to the smaller lower sites to help them grow and become the new main stem.. If done right you can end up with multiple main stems shooting up with little to no stress on your plant, in turn slowing down the growth as little as you can for a faster and bigger harvest! Happy growing!