It really depends on what your trying to do. If you're trying to harvest them quickly then you can use LST because topping a plant will stunt it's growth for a little while. There are many different techniques for different situations.
I have limited space but a high-yielding plant that does well with topping once. So on my next grow I will top at about 3 or 3.5 weeks and then scrog for another 4 or so before flipping.