For me, the best way to build is to have an end goal in mind. Putting bricks together is great and all, don’t get me wrong. But if you don’t know where you want to end up, how do you expect to get off on the right foot?
That said, there should be some thought that goes into a model before the building process is begun. I usually start a model with extensive research on the prototype. For the purpose of this article, the example model will be a Pennsylvania Railroad BM70m baggage-mail car.