Only one plant per container!!!!
I pinch after the 5th set of true leaves, so at the 6th node, if I'm pinching at all.
Otherwise I let the plant grow single-stem and keep bending the growing tip[ so it points downwards, like a horeshoe, and the side growth is exposed to more light and takes off.
I pretty much see what the plant wants... if it is a strain with a crazy thick stem and vigorous side branches, it gets pincehd early. For example PPP, MTF, or Skunk#1. If it is more flexible, it gets trained over. The example of this is OG Kush, that has a relatively bendable stalk and seems to LOVE training.