I started using tomato cages a few months ago, not the big heavy metal ones, the thinner green ones with the plastic coating. Anyhow, I fim the first time when the top shoot is about 6 inches tall. The I usually top 4 branches a couple weeks later. I veg for a total of 5 weeks and then lollipop and flip them when they are about 18 inches tall, giving me 8-12 good colas inside the cage.
But when this next batch of cuttings roots, I'm going to pick up (or make if I can't find one) one of those plant support things where it's like a 8 inch tomato cage but only has one ring going around the top and sits about 8 inches above the soil. Then I'm going to see if I can train the branches that grow from where I FIM to grow horizontally and around it so that when I top the tips off, all the other bud sites will grow up at the same time.
Haven't done it yet though. But having great results with the cages either way, I prefer this over SCROG (which is great) because I can still move around my plants.