Writing Tip #4: Use a structure
For some writers, having a structure in place first makes the writing easier. These writers prefer to think things out ahead of time and then build to a plan.
Other writers put down all their ideas in a glorious profusion of words. Papers maybe spread all over the house, the car, the office desk, and fishing tackle boxes... These writers like to see all the material and then build the structure.
Both approaches work well depending on the personality of the writer. both kinds of writers need to end up with a structure that supports the reader's understanding.
There is no one right structure for a book any more than there is one right structure for a house. Some will be linear, and take the readers step by step directly through to a conclusion like a long hallway opening into a inner courtyard.
Others will feature a spiraling staircase that takes the reader around and around the topic, always climbing higher to the secret chamber at the top, or to the rooftop view where everything becomes clear.
The fair thing is to do is to use a reasonable route to the destination. It's unfair to take your reader up the staircase to the fourth floor and then to push him out a window so he can enjoy the inner courtyard.