Just say no to tomato cages! I hate the damn things, refuse to have anything to do with them. When you transplant, how much do you bury/leave above ground? I always bury almost the entire plant when I transplant (leave 2-3 inches sticking out) and tie that little bit to a sturdy stake and then let the plant spread as it wants. I know that's not always feasible but it sure makes for some massive/productive plants.