When we talk about formal strategies in fiction, we are talking about the form of the novel (or story), the ways that the author chooses to organize and structure the work, and the conventions used by the author. The simplest definition of “formal strategies in fiction” can be stated as the ways in which an author organizes, plans and structures a work.
Chapter divisions, book parts, and other structural elements like these are examples of formal strategies in fiction.
Discussions of formal strategies often abut upon discussions of style decisions made in fiction. There is large area of overlap between these two categorical concepts, style and form, and some of the literary devices that fall in between are flashbacks, symbolism and motif.
To go further into style discussion, we might talk about modes of characterization, word choice/language choice, and, personification, metaphor.
If we focus specifically on symbolism when studying a text or a writer, we will want to look at the formal and functional aspects of the use of symbolism as it relates to theme, plot and character.
For instance, in Waiting for the Barbarians the magistrate’s trek into the desert to return the barbarian girl to her people serves a number of functions, including a symbolic one.
This journey, formally speaking, functions as the mid-point of the novel, marking a passage of the magistrate from a figure of power and culture to a person devoid of authority and powerless. In handing the girl back to the barbarians, the magistrate symbolically terminates his position of advantage.