An effective and compelling narrative flows organically from start to finish. The opposite of this is a story that feels overly wrought by an author; that is to say, artificial.
A good plot is always organic (The Anatomy of Story, John Truby)
plots ought (…) to be constructed dramatically; that is, they should be concerned with a unified action (Poetics, Aristotle)
To achieve this ‘unified action’, cause and effect should be used to drive the plot onward. A useful tip for conceiving cause and effect is to connect each major beat using the word ‘therefore’. This would be done within the plot’s outline. For instance:
Gandalf encourages Bilbo to give up the Ring; therefore, Frodo becomes the ring bearer.
Wraiths enter the Shire to locate the Ring; therefore, Frodo leaves for the safety of Rivendell.
A conclave at Rivendell concludes that the Ring must be destroyed in Mount Doom; therefore, Frodo begins his journey toward Mordor.
Should a story need to lose its cause-and-effect momentum, such as in a nonlinear narrative, then the use of foreshadowing and implication can foster a sense of narrative interconnectedness.
In Michael Ondaatje’s The English Patient, the narrative is divided between present scenes and flashbacks. During the present scenes, the English patient reflects on his affair with Katharine; these scenes increasingly foreshadow a series of tragic events yet to occur in both the present and past. The effect of this foreshadowing is that the entire narrative flows with an organic cause-and-effect feel, despite the narrative’s disjointed structure.