long veg good lights good nutrients good temps good air flow supercropping if you know what your doing. theirs so many different things that you could do.
Bending the branches and folding them over. Like topping and LST without cutting or tieing.
I say good genetics, and a dialed in grow area (SCROG and LST are good for yield NICE EVEN CANOPIES). will work best for you.
Adding CO2 in the upwards of 1200ppm during lights on will increase yield as well.
Theirs really to much you can do to really answer your question. Maybe shoot up some detials like area, lighting , plant numbers and what you would like to achieve as far as yield and someone could answer you better.