The impetus of almost all writing is conflict. With fiction, conflict drives the characters, moves the action, and keeps the reader turning pages. With nonfiction, the conflict usually involves the reader needing to know something that the writer can provide—or presenting a problem that the paper will solve. In a sense, writing presents a knot at the onset, and the writer spends the rest of the piece untying it.
Many books on writing attempt to quantify the types of conflict that can exist (human vs. human, human vs. tuna fish, etc.); however, the main point is that conflict creates a sense of unease in the reader, a disequilibrium that demands to be made right. Typically, when you set out to write something, your idea will inevitably have some sort of ingrained tension, such as:
Story plot: A man fights to save his family against giant marshmallows.
News story topic: Who are the perpetrators responsible for drawing a mustache on the Mona Lisa?
You typically won’t need to worry about inventing conflict, since it tends to shake out of the very premise of the piece you’re writing. However, there are some points to keep in mind about conflict.
Initial action: In nonfiction, the initial action is simply setting up the problem that the reader needs to find out the solution for or information about (e.g., test results, news, procedures, tech specs). With fiction, the initial action is what sets the conflict in motion, which can happen even before the story begins. In the novel that I’m currently working on, the initial action involves the main character beginning his journey to see his brother. This happens before the narration begins, but that decision puts him on the road (literally) to everything that happens from there on out.
Building action: Building action simply involves moments of smaller resolution that also contribute to compounding the issue at hand. It is much like a mountain climber finding a ledge on which to rest. She has made it to a waypoint, but this just emphasizes the mountain is still not conquered. This may not be quite as appropriate in most nonfiction, though you can certainly lead the reader to a possible solution and reveal that this solution won’t quite cut it, for example. In fiction, these are often events that provide some clarity (e.g., the detective finds a clue) but also provide either more action or more suspence (e.g., the clue makes his own brother a suspect).
Climax: Once you have strung the reader along, there must finally be a moment of resolution: how the product will solve all the reader’s problems, how the news event turned out (news stories often present the problem and resolution in the first paragraph and then rehash). With fiction, this is the ultimate last stand when the Death Star is finally destroyed and the Emperor is defeated. There may be action after this (living happily or not ever after), but the main tension is resolved.
Just remember: conflict gives your writing shape. Use it to enhance interest in your writing.