Apparently, the two most common textbook metaphors for writing (USA) are building a house (esp. a log cabin) and taking a journey. This metaphors are applied to both process and product. The house metaphor is too structured and linear: it implies that one can draw up the blueprints (OUTLINE) and order the materials (RESEARCH?) first, before starting contruction ("ACTUAL" WRITING), that framing preceding plumbing, etc. The journey metaphor also suggest more linearity than is typical of writers' processes and implies that wandering (DIGRESSION?) is inefficient, perhaps even that one knows the destination before starting out.