Techniques for growers who already have a working room: shaping the plant rather than simply feeding it. Topping and mainlining, low and high stress training, screen and sea of green layouts, defoliation, and the mother and clone cycle behind all of it.
Every method here is an answer to the same problem, which is that a cannabis plant left alone puts most of its energy into one dominant top while the light falls on empty space around it. Training redistributes that, and the choice between methods is mostly a choice about how much time you have and how many plants the room is allowed to hold.
Two things separate the techniques that work from the ones that cost a crop. Timing against the flowering stretch decides almost everything, because a plant that is cut or bent too late in the transition does not have time to recover, and the stretch itself is largely genetic rather than adjustable. And defoliation is the most argued-about method on this board precisely because the evidence is thin: it removes photosynthetic capacity in exchange for light penetration, and the trade only pays under specific conditions.
Where to start