See, what the author is doing is exploring an issue. This is more thematic than structural, but the decision to explore this issue helps select (and de-select -- what DO you think of that as a verb?) plot events, and shape them to explore this issue more.
The issue in this book is "power". This takes place mostly in a courtroom, and the power is mostly about the power of the judge, and there's an implicit question revealed as the story goes on: What happens when a sociopath becomes a judge? (Answer: He uses the over-the-top power of a judge within the courtroom to send his lover's husband to an asylum and the attorney to jail.) But it's not just power as in power over others. There's the related issue of "control" (power over oneself). The attorney thinks of himself as utterly in control of his demeanor, attitude, courtroom performance. He's proud of his ability to control the responses of witnesses by asking questions in just the right way. And he has sympathetic scorn for his friend the alcoholic (who keeps talking about how you have to accept your own powerlessness) and scornful sympathy for mental patients who have no control over themselves. In fact, almost everything in the story has a bit of a "power" resonance, either power or the lack of power.
Identifying an issue to explore (or that is being explored) can help us select events and even the trajectory of the journey. For example, where does the story begin? Maybe, if we're exploring the issue of power, we want to start with an event that has to do with power. (The thriller starts with the judge's murder-- lack of power-- suggesting it is the result of the real opening, the main character's recollection of this judge sending him to jail-- abuse of power.) And even the romance is about this issue-- the protagonist seems to will himself to fall in love, and then finds out that he actually doesn't have much control at all. He thought he could control the volatile nature of human interaction. No luck. :) Then other aspects of power might be explored throughout the story-- the powerlessness of defendants in the courtroom and of abused children, the machiavellian power of one brilliant seemingly powerless mental patient.
Once we identify an issue that's being explored, we can emphasize that in scenes. For example, Huck Finn is all about family-- blood families, adopted families, chosen families, fake families. Where does the story start? Huck has been "adopted" by the Widow Douglas, but when his birth father arrives back in town, a judge who believes that family is all about blood transfers custody. In contrast to the Widow Douglas's selfless if clumsy parenthood, the motivation of Huck's father is to get Huck's cache of gold. He is drunken and abusive. Clearly the "birth family" is no ideal.
And in fact the adoptive family, though better for Huck, isn't an ideal either. Huck runs away and meets up with Jim, a slave of the Widow's sister. He has overheard her talking about selling him away from his own family, and has fled hoping to find freedom and bring his family back together. "Family" is presented for both Huck and Jim as the opposite of "freedom".
In this picaresque novel, plenty of things happen, of course. But Twain textually and subtextually connects almost every event with some aspect of "family." So in the beginning, while Huck chafes at the confinement of his adopted family (and is soon literally chained up by his father), he longs for the chosen bonds he's forged with Tom Sawyer (his "brother") and Tom's new "robber gang".
Here's how Twain describes the initiation into Tom's gang. Notice how he makes it about "family."
Everybody said it was a real beautiful oath, and asked Tom if he got it out of his own head. He said, some of it, but the rest was out of pirate-books and robber-books, and every gang that was high-toned had it.
Some thought it would be good to kill the families of boys that told the secrets. Tom said it was a good idea, so he took a pencil and wrote it in. Then Ben Rogers says:
"Here's Huck Finn, he hain't got no family; what you going to do 'bout him?"
"Well, hain't he got a father?" says Tom Sawyer.
"Yes, he's got a father, but you can't never find him these days. He used to lay drunk with the hogs in the tanyard, but he hain't been seen in these parts for a year or more."
They talked it over, and they was going to rule me out, because they said every boy must have a family or somebody to kill, or else it wouldn't be fair and square for the others. Well, nobody could think of anything to do -- everybody was stumped, and set still. I was most ready to cry; but all at once I thought of a way, and so I offered them Miss Watson -- they could kill her. Everybody said: "Oh, she'll do. That's all right. Huck can come in."Then they all stuck a pin in their fingers to get blood to sign with, and I made my mark on the paper.
Later Huck uses the excuse that his father has smallpox as a way to escape from attackers. Again, this is a casual but purposeful use of "family." Huck could have said that anyone was the smallpox sufferer (he'd made it all up), but he said his father-- a family echo.
In another "family" example, Huck meets a nice family (the Grangerfords), which is family enough, sure. But Twain chooses to have them in a feud with a neighboring family. The latest complication of the feud? The boy of one family and the girl of another fell in love and ran off together (creating their own family and joining the two families, whether they liked it or not).
And the duke and the dauphin seem like garden-variety (if oddly erudite) con men. But what's their next con? They impersonate brothers seeking to collect on an inheritance, and trying to scam a set of sisters.
Huck and Jim then stumble on a family of nice people who not-so-nicely are planning to "sell" Jim back to his owners to collect a reward. However, they mistake Huck for their nephew Tom (yes, THAT Tom), who is set to arrive. Huck goes along with the error in order to protect Jim, and when Tom arrives, he has to take on the masquerade of his own little brother Sid. In this complicated way, Huck finds himself truly (well, sort of) the "brother" of the boy he has thought of as a brother-- the sibling relationship is made real (though of course it's not :). The fractals here of real and artificial and created families become ever more complicated. But always "benevolence and love" win out over blood, as Jim ends up sacrificing his chance at freedom to take care of Huck.
(And Huck, btw, rejects the family, both invented and adopted, and chooses freedom. But Twain has him specifically choosing freedom over family.)
Always keep in mind that you as the author have choices. You can choose to have the hero escape through a window or through a door. You can choose to have the dispute about a will or about a loan. You're in charge here. Think about making some choices reflect the central issue under consideration.This will give you more direction in scene design, and help you make the story more coherent and meaningful. You don't have to know the "theme" of the story to accomplish this. You just have to identify for yourself a major issue you want to explore.
So everyone identify an issue you're exploring! I'm working on a romance where I think the major issue is "self"-deception. I don't mean so much deceiving yourself as deceiving others about who your-self is. So the heroine has kept secret her identity, and let the world think she's just another housewife. Only the hero knows that there's something more in her. But I think I'll play with the whole issue of masked identity, of people hiding behind nicknames and false names, and hiding who they really are.
What about your story? What's an issue you're going to explore?