I start by pruning a leaf from each node in a staircase pattern, as soon as the first 5 bladed leaf appears. This will stimulate lateral growth and open the plant to more light.
I top around the 4-5 node, using the FIM technique, leaving about 20% of the growth tip intact. Topping will create at least 2 new budding sites, and with proper use of the FIM technique I have had as many as 5, and have heard of as many as 8. Topping will allow bottom branches time to grow and catch up, making them closer to the lights.
With proper training and manipulation, you can get these giant plants to grow horizontal, effectivly reducing the overall height of your garden as much as 50%. This way you can lower the lights as close as possible to all budding sites. With many budding sites very close to the light, you will get a better yeild of grade "A" bud. As opposed to having smaller shaded buds trapped under an untrained canopy, which will never fully develop.