[Threshold]

Yes, that is the traditional way to get new builders. It is time tested and it certainly guarantees that the builder is very familiar with the world and its lore. Obviously, a new game does not have this luxury. This does, however, bring with it drawbacks of its own: making sure your builders do not let biases and preferences from their playing days affect their building.

So far, this appears to be the clear winner for the most important thing to do when working with your builders. I definitely agree with this as well. Planning things out in advance and talking about a potential idea really is the best way to avoid problems. Just sending off builders to "go make something cool" is a recipe for disaster.